Abstract:
The appliance designed to allow a living being to perceive sensations of virtual movements of part of his body comprises a control unit in which is stored a table containing a first plurality of basic excitation signals, a second plurality of macro-motifs each formed by a third plurality proper of the basic signals, a sequencer reading the macro-motifs in order to emit a second plurality of corresponding commands for excitation, each time, of a third plurality proper of vibrators selected from among a first plurality of vibrators carried by a coupling support in predetermined respective zones of the part of the body, the excitation of the third plurality proper of vibrators by the second plurality of commands being intended to mechanically stimulate elements of the body, to provoke the creation of bioelectrical signals in the living being, allowing him to perceive sensations of a given virtual movement.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Phase Entry of International Application No. PCT/IB2009/005330, filed on Apr. 22, 2009, which claims priority to French Application 0802242, filed on Apr. 22, 2008, both of which are incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to apparatus capable of generating sensations as perceived by the brain during the performance of a movement affecting part or all of the body of a subject, while this same part of body is not actually being affected by any movement. The present invention concerns, inter alia, physical rehabilitation of persons, even certain animals, a damaged limb, or any other body part, part of which is immobilized by a corset. The present invention also relates to education and rehabilitation on functional movements that the brain no longer knows how to perform, or performs imperfectly, as a result of injury which is accidental or resulting from an illness, or due to a malformation. 
     The present invention also relates to the learning by an individual or an animal, of a body movement or gesture which has a specific purpose. It also relates to the addition to an individual&#39;s or an animal&#39;s received perception of a situation or a virtual event, of an additional type of sensory information. The term “virtual reality” is commonly used to describe such a confrontation of a subject with images, sounds and other types of sensory information, providing a descriptive representation of the situation or the virtual event. The invention is capable of causing a subject to perceive sensations corresponding to those of movement, whether or not the subject is performing these movements, which in effect constitutes additional sensory information for perception of virtual reality, and thus an enrichment of this perception. 
     A person with a broken upper or lower limb, or injured ligament, is usually fitted with a rigid corset that immobilizes the affected limb, such as a joint. When the corset is removed after a few weeks the relevant joint muscles are incapable of operating the movements they allowed prior to immobilization of the joint. This is due, firstly, to the fact that the muscles were injured or unused and, secondly, the fact that the brain has lost some of its ability to manage movements resulting from these muscles being brought into play. Indeed, many studies have shown that certain brain networks assigned to this task are progressively reassigned to other tasks if they fail to receive nerve messages sent by the skin and muscles when working. Physiological receptors located notably in the skin and muscles are responsible for issuing bioelectric messages to the brain. Specifically, some of these receptors are between muscle fibers and are located so as to be sensitive to the extension of the muscle. These messages are “reports” that describe the detailed movement of every muscle, so the brain can, in turn, have a representation of an action and control the muscles to eventually correct their movement and also to guide further movement in the desired direction. 
     Writing is a good example of such a feedback loop. The writer is simultaneously contracting or extending a number of muscles of the hand and wrist, all these elementary movements requiring, of course, to be perfectly coordinated. The brain senses, notably, messages issued by each muscle involved and the skin in case of extension, and it makes a synthesis of this information to determine what was, until then, the movement made, ie the path followed, in the case of writing. 
     SUMMARY OF THE INVENTION 
     The present invention sets out in particular to reduce the need for physical rehabilitation when part of the body of a living being, especially a human being, has been immobilized. It can also help correct a deficiency or inability to perform movements, whether these result from an injury or malformation, of the musculoskeletal system and nervous system. To this end, the invention firstly provides apparatus, especially for physical rehabilitation of part of the body of a living being, comprising a control unit comprising a table held in memory containing a first plurality of elementary excitation signals being elements making up a second plurality of macro-patterns each consisting of a third specific plurality of said elementary signals, the control unit including a sequencer adapted to read the macro-patterns and issue a said second plurality of corresponding command excitations for a said third specific plurality of vibrators selected, on each occasion, from among a said first plurality of vibrators carried by a coupling support in respective predetermined areas of the part of the body. 
     Each macro-pattern consists of a set of elementary patterns each representing the form or shape of a signal controlling the movement of one of the vibrators, that is to say a mechanical means for exciting a point on the skin and/or any physiological receptor structure located below such as a tendon or muscle. Macro-patterns are determined from recordings made previously in humans or are synthesized macro-patterns, prepared by composition of elementary patterns, the shape of each having been optimized to emulate a determined movement. 
     Each of the vibrators, applied to the skin, will thus stimulate a set of physiological receptors, that is to say a particular point for example of a tendon associated with a damaged joint, this stimulation being performed with a direction, intensity and frequency constituting an equivalent number of parameters in selecting each elementary pattern memorized. Variation over time of this stimulation and the multiplication of points of stimulation constitute many of physiological receptor stimulations. It is thus the combination in space and time of these simultaneous stimuli, that is to say, applied at various points on the skin to excite the underlying tissue, which will supply the brain at any moment, with a “neurosensory flow” type dataset, that is to say that the brain receives sensory messages from the various tissues excited that depend on the amplitude and frequency of the various vibrations, which constitute an emulation of the effective extension of the immobilized muscle, of the stretching of the skin and of the perceived displacement of the limb. Neural networks of the brain areas under consideration will regularly receive such information, at the rhythm set by the sequencer, and the thus ensured continuation of the corresponding processing task will make that these neural networks will remain, at least in large part, assigned to the processing of sensory flow originating from the muscles under consideration, since the immobilization of these will be masked in this way. 
     After healing of the muscle or joint and its consequent release, rehabilitation will only essentially be mechanical, that is to say focus almost exclusively on recovery of the full force of the muscle, since the brain will have preserved the corresponding network for representing and managing movement. As mentioned above, each macro-pattern may include data specifying a modulation of amplitude and/or frequency of movement of the vibrator over a predetermined period of excitation. Preferably, the sequencer is mechanically independent of the coupling support, and is connected to the vibrator by a data link. The vibrators are for example controlled through a respective transponder. We can thus equip an injured person with a sort of harness keeping the vibrators at the desired location, the problem of immobilization being handled by a sleeve or other component external to the apparatus of the invention. 
     In general, the only elements necessarily worn by the patient are the vibrators with their coupling support. As against this the macro-patterns can be perfectly well stored in a common server shared by several such apparatuses. The common server can contain a complete library of all types of macro-patterns, that is to say for all types of limbs or other body parts that may need treatment. For the treatment of a specific limb, the sequencer will choose the appropriate set of macro-patterns. 
     The link for providing the macro-pattern to vibrators may be operated by cellular telephone or data transmission network link circuits. It will be recalled that a mobile phone includes a port for data exchange, which in this example, can be connected to a logic unit for management of data exchange and control of the vibrators. One can also consider a link such as the Internet, preferably with a wireless terminal link, that is to say of the WiFi or equivalent type, in order to permanently maintain the ambulatory aspect. A person in ambulatory care at his home, for example, can receive data messages containing the appropriate sequences of macro-patterns. The above management logic, forming a sequencer and a local transmitted bit format and bit rate adapter, will then store the data bits reflecting the sequences of macro-patterns received over the high-speed network, and will restitute, in non-real-time, these data in a desired format compatible with the vibrators, and at the desired speed. 
     The apparatus of the invention described above may be provided to limit the need for physical rehabilitation after immobilization of all or part of the body, for example following a fracture, an injury or disease. It can also be provided to lessen the consequences of prolonged bed rest, keeping neuronal circuits active for processing messages descriptive of fundamental movement, such as for maintaining a natural posture or for locomotion. Moreover, it was found that implementing the apparatus according to the invention on a subject so as to give his or her brain messages descriptive of the same movement repeatedly, is capable of gradually inducing performance by the subject of the said movement. This property can be used to enhance or correct the repertoire of gestural knowledge recorded by the brain and make it possible to learn an unknown gesture, or to perfect a gesture which is imperfectly performed. 
     The apparatus of the invention can thus be provided as a means for physical rehabilitation by providing descriptive messages to the brain of a movement that the brain does not know or can no longer perform, or only performs imperfectly. Such situations can result from damage due to sickness or accident, or result from a malformation. Such neurological damage, whether accidental or degenerative, can affect the central or peripheral nervous systems. This apparatus can in particular be adapted to deliver the messages that match descriptions of the movements of locomotion. In this particular case, having identified the muscles involved, the vibrators are held in position by a suitable coupling support adapted to transmit stimuli to the appropriate physiological receptors according to the excitation signals provided by the reading of macro-patterns specific to walking. Another application of the apparatus of the invention consists in re-educating how to maintain a particular posture or body position in a living being, such as standing upright in human beings. 
     The apparatus of the invention can also be provided to allow the learning or fine tuning of complex body movements, including those requiring precision. We can cite for example writing, body movements associated with a sporting activity, the serve in tennis or the golf swing, or with a professional or artistic activity. Such learning or fine tuning may also apply to the performance of body movements under conditions different to the usual conditions of a subject. These include the conditions corresponding to free fall or weightlessness and microgravity, increased gravity and acceleration. 
     Such apparatus can also be used in the framework of virtual reality. Indeed, the mobilization of a greater number of sensory channels contributes to improving the quality of perception of virtual reality experienced by the subject, human or animal. As an addition to the usual channels such as vision, brought into play by the picture, hearing brought into play by sound and sometimes touch through various pieces of mechanical equipment, the apparatus of the invention can be used to add sensations of movement, and thereby enrich the description of the situation corresponding to the virtual reality which the subject is facing. 
     The apparatus of the invention can be designed to be part of a production system for virtual reality. Among such systems, we can notably mention video game consoles and simulators of all kinds. Among the latter, we can mention flight simulators, simulators for driving all kinds of machinery, for industrial process control, simulations of extreme conditions, such as weightlessness and ultragravity, simulators of complex and very precise movements such as in surgery. The virtual representation production system including apparatus of the invention which is functionally integrated therein, combines calls on the user&#39;s sensory channels with sensations of perception of virtual movements. Indeed, this system will supply messages to the brain carrying sensory information corresponding to movements of the body represented by the virtual reality generated by the system, and with which the subject is confronted, giving the impression of performance of these movements whether or not the subject is actually performing or not the said movements. This is achieved through a recording and analysis of movements to which it is desired to give the impression of performance and identification of the muscles brought into play by them. The macro-patterns specific to each specific movement are used to take control, every time such a movement is the result of the virtual situation shown, of the vibrators being held in position appropriately so that they stimulate, when asked to, the tendons of the muscles involved by this movement. 
     The apparatus of the invention includes means for holding the vibrators in contact with the skin at the desired location, or a coupling support. It is possible to adopt many embodiments for putting into practice the function of this coupling support, which depend to a great degree on the use made of the apparatus. Practical embodiments can take such forms as a harness, a body suit, a full or partial garment, with a material and design appropriate to the use. A harness may for example take the form of a set of straps fitted with adjustment means to adjust the position of the vibrators, and the contact characteristics of each vibrator with the skin. In addition, the coupling support may perform one or more other functions exhibiting synergy with the particular use made of the apparatus of the invention. Notably, the coupling support can operate, functionally, restraint or immobilization of a body part corresponding partly at least to the part subject to stimuli. 
     The invention thus relates generally to apparatus for generation of bioelectric signals, providing a living being with sensations corresponding to the performance of a given movement of a body part ( 1 ) even if this movement is not performed, comprising:
         a table of elementary excitation signal,   a control unit including a sequencer,   vibrators carried by a coupling support maintaining each of them in a predetermined position relative to body elements of the body part,   in which, for each given movement, each vibrator can receive an elementary excitation signal that stimulates mechanically body elements of the body part to cause bioelectric signals to be issued, all elementary excitation signals of the various vibrators constituting a macro-pattern, these elementary signals being chosen to form a specific macro-pattern characteristic of the movement under consideration, this macro-pattern read by the sequencer supplying said vibrators with the elementary excitation signals capable of causing the creation of bioelectric signals in the living being causing him or her to perceive the sensations of performance of said movement.       

     The invention also relates to a method for making out of macro-patterns for exciting the apparatus according to the invention, in which method tests are performed on at least one subject,
         by applying stimuli in the form of vibrations resulting from a first macro-pattern determined in advance, for a body part under consideration, simulating, virtually, a determined movement,   the subject indicating his or her perception of the virtual movement thus evoked by the stimuli,   and, by successive iterations, with change of the parameters of the first macro-pattern, determining the final values of said parameters corresponding to a satisfactory emulation of the real movement simulated, and   having repeated the previous cycle of steps a desired number of times to obtain the desired number of macro-patterns, the parameters for these are stored in the said table.       

     It may in particular be determined what muscles exist in the body part in question and successive cycles continue to be executed until a sufficient number of macro-patterns have been built up so that each of said muscles is handled by at least one macro-pattern. The invention also relates to a use of the apparatus of the invention, in which the apparatus is functionally integrated with a video game console in order to emulate, for the user, movements to an avatar of the user displayed on a screen. 
     The user can thus perceive the movement of his or her avatar and possibly voluntary movements the user performs or blows received. In a sophisticated usage, the user wields a three-directional (3D) accelerometer to control the movements of his or her avatar, that is to say he or she controls the game by their own 3D movement, in direction and intensity, and perceives it or only the avatar&#39;s contact with the environment (impact with a wall, a combat fight) using the apparatus of the invention. The user&#39;s perception of events displayed on screen is thus simultaneously visual, tactile and accompanied by motor sensations, with sensations of local acceleration, that is to say movement. It will therefore be seen that these two parallel and complementary channels for perceiving the environment provide a way of intensely immersing the user in this augmented visual environment. More generally, the invention relates to apparatuses and methods as defined in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood from the following description of an embodiment of an orthotic apparatus implementing the method of the invention, with reference to the accompanying drawings in which: 
         FIG. 1  is formed of  FIG. 1A , a block diagram illustrating the context of the invention in the form of a loop for transmitting information between a tendon associated with the orthosis and the brain, and a  FIG. 1B  illustrates more precisely the shape of the orthesis; 
         FIG. 2 , consisting of  FIGS. 2A ,  2 B and  2 C, shows three examples of time signals reflecting the letter “a”; 
         FIG. 3 , consisting of  FIGS. 3A ,  3 B and  3 C, shows a joint under consideration for a subject for respectively  FIGS. 2A to 2C ; 
         FIG. 4 , consisting of  FIGS. 4A ,  4 B and  4 C, is the handwriting of the letter “a” above, corresponding respectively to  FIGS. 3A to 3C ; 
         FIG. 5  shows a foot associated with various directions of sensation evoked by the vibration of various tendons; 
         FIGS. 6 and 7  each show five temporal patterns of signals from different muscles, respectively, when we draw the letter “a” and the digit  8 , on each occasion with a natural signal detected and the same signal after processing; and 
         FIG. 8 , consisting of  FIGS. 8A ,  8 B,  8 C and  8 D, respectively comprises four lines of the same four digits and the same four elementary letters, showing the perception gained therefrom when implementing macro-patterns. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1A  is a diagrammatic view illustrating the context of the invention. The muscles of the foot  1  in a movement of a person, seen here from the right, and more precisely tendons  2  conventionally issued, to the brain, elementary signals signifying the movement in progress, that is to say, the trajectory and speed of the foot  1 , in the form of its overall advancing movement along with its rotational movements.  FIG. 1B  shows, seen from the left, in more detail the shape of the orthesis, which closely outer housing the foot and lower calf. 
     It should be remembered that, conventionally, the movement of any object can be defined by reference to six types of movement, namely three translations along respectively, three orthogonal axes, such as a vertical axis and two horizontal axes defining a front/back direction and a lateral direction, and three orthogonal axes of rotation. Movement was caused by voluntary control from the brain or by reflex action. The signals received back from the brain are a report of the movement performed, so that the brain may if needs be send a correction command for correcting a movement that it considers inappropriate or to follow up with a continuation of the movement. This is especially important to synchronize walking. The brain is well accustomed to handle such signals. However, when there is immobilization of the limb, following a sprain, fracture or other, the brain no longer receives such signals and neural networks which used to process them are gradually diverted to other tasks. 
     Such elementary “movement” signals received by the brain have been picked up by electrodes inserted in the nerve, close to sensory fibers originating from physiological receptors, and stored in a database  10 . The total number of tendons  2  defines in this way a first plurality, of size P 1 , of such elementary signals, and any particular movement M 0 , from a second plurality P 2  of possible movements, corresponds to a proper subset constituting a particular set made up by a third plurality P 3  of elementary signals belonging to the first plurality P 1 . Each third plurality P 3  is size-specific to the movement M 0  under consideration from the second plurality P 2 , since it consists of those of the elementary signals that are specific to this movement M 0 . In this present description, reference numerals to a plurality P 1 , P 2  or P 3 , each of which covers different types of elements, means only the number or size of the plurality, while the nature or type of the elements is indicated by the terms associated with the reference. 
     By way of numerical explanation only, we have for example a first plurality P 1  of 5 tendons  2  to monitor (only tendons  22  being shown), that is to say, a first plurality of elementary signals P 1  to acquire through 5 acquisition channels. A first determined movement M 1 , from the second plurality P 2  of movements, for example reflecting  10  movements M 0 , will for example cause a reaction on a said third plurality P 3  of channels that will for example constitute channels ranging from 1 to 4, while a second movement M 2  will cause a reaction on another third plurality of channels P 3  formed by channels ranging from 3 to 5. This shows that the third pluralities P 3  of channels, and therefore also of elementary signals are of disparate sizes, here of respective sizes 4 and 3 channels. Each one of the P 2  third plurality P 3  of elementary signals forms a dataset, of size P 3  (number of elementary signals) specific to the movement in question M 0 . The second plurality of movements P 2  can be much larger than the first plurality of elementary signals P 1  since the various (P 3 ) datasets of the second plurality P 2  of movements are each formed by specific combinations and of sizes P 3  which are mutually different, of said elementary signals encompassed in the first plurality P 1 . 
     To identify each of these elementary signals, there have been identified during testing, a first set of movement types, as a number of relevant signals forming the first plurality P 1 . For each movement M 0 , that is to say every third plurality of elementary signals P 3 , a mean for each one of the elementary signals has been determined that is to say, smoothing out of differences due to various causes, such as size or morphology of the subject has been determined. Reference numerals  11  and  12  thus designate, each one for a particular movement M 0  among the P 2  movements, a said dataset containing a third plurality P 3  of such elementary signals, the two datasets  11 ,  12  corresponding respectively to two representative or “standardized” movements, M 1  and M 2 , determining the size of the second plurality P 2 , which is then P 2 =2, to simplify this presentation. Obviously, this is a simplified representation, since a much larger second plurality P 2  of datasets had been established containing a third plurality P 3  of movement signals M 0 . Each third plurality P 3  of signals of a dataset  11  or  12  consequently represents all elementary signals sent by different tendons  2  during the movement M 0  under consideration. As indicated, various third pluralities P 3  are generally of different respective sizes, that is to say that every movement M 0  involves a number of tendons  2  specific to it, for example on each occasion from three to five out of a greater number (P 1 ) of existing tendons  2 , but for which the other tendons  2  are not relevant to the movement M 0  under consideration. In short, this ascending branch, to the brain, implements a transducer function, with a passage from the field of mechanics, specifically kinematics, that is to say an area of “action” to the field of bio-electric signals, specifically the field of information or knowledge, with the analysis of signals by the brain. 
     One basic idea was to examine if one could perform the reverse transformation, starting out from the database  10  which is a descriptive library of bio-electric responses to the various (P 2 ) movements M 0 . The value of this would be the possibility of creating these same second pluralities P 2  each of P 3  signals, giving sensory feedback to the brain when the body part in question, here the foot  1 , is immobilized by a coupling support  3  here in the form of a sensory feedback orthosis constituting a corset applied to a foot, wounded, in order to thereby preserve the corresponding signal analysis activity at the brain. To do this, a descending branch is defined, from the database  10  to the foot  1 , an upstream section of which is purely electronic and a downstream section of which is of an electric-mechanical type for transforming control electrical signals into mechanical stimuli at the tendons  2 . The database  10  controls a transcoder  20  which itself controls writing into a memory  30  of a said second plurality P 2  of macro-patterns  31 ,  32 , each containing a said third plurality P 3  of elementary signals, macro-patterns  31 ,  32  being defined to have a bijective relationship with the respective datasets  11  and  12  of each movement M 0 . 
     The memory  30  is part of a control unit  40  managed by a central unit  42  driven by a timebase  41  and associated with a sequencer  43  connected to read macro-patterns memory  30 . Each macro-pattern, among the second plurality P 2  of macro-patterns  31 ,  32  each containing P 3  electronic control patterns, can thus control via a link  49  having a said first plurality of channels P 1 , a said third plurality P 3 , specific to it, of transducers  51 , or transponders, chosen from a said first plurality P 1  of transducers  51 . The first plurality P 1  of transducers  51  controls a said first plurality P 1  of respective associated vibrators  61  applied in various predetermined positions on the muscles of the foot  1  and in particular on the P 1  respective tendons  2 . In other terms, the fact of a dividing into first P 1 , second P 2  and third P 3  pluralities this downstream section of the descending branch, electronic and mechanical, is the image of what exists on the ascending branch, through the body.  FIG. 1B  shows that the vibrators  61  are located under the outer housing forming the orthesis and applied to the associated tendon  2  under a coupling adjustments screw  61 V. 
     The first plurality P 1  of pairs of transducers  51  and vibrators  61  is thus of a sufficient number allowing all the types of elementary signals that are in the database  10  to be produced. Note however that there may be even more transducers  51  and vibrators  61 , that is to say a fourth plurality greater in number than the first plurality P 1 , if, for example, it is planned to combine vibrations from several vibrators  61  for obtaining a composite vibration in an optimal composite direction, reflecting the direction of maximum sensitivity of a tendon  2 , that is to say to which it supplies in response, to the brain, an elementary signal of maximum amplitude. Specifically, macro-pattern  31  or  32  selected to emulate, vis-à-vis the brain, a movement M 1  or M 2  forming part of the second plurality P 2 , will control one of the second pluralities P 2  forming part of the first plurality P 1  of transducers  51 , in order to mechanically stimulate those ones of the tendons  2 , or other parts of the body, which normally generate the elementary electrical signals in response to the actual movement M 1  or M 2  under consideration. 
     In feedback system terms, the loop formed by the ascending branch, from the tendons  2  to the database  10 , and the return descending branch, has a unity gain, that is to say that the descending branch is capable of producing, and delivering to the tendons  2 , signals of a mechanical nature which cause, in reaction thereto, the generation of elementary biological and electrical signals, and, in addition, the descending branch is arranged so that the elementary electrical signals, induced by reaction at the tendons  2 , are substantially identical to the original elementary signals, ie those which, after digital encoding, form datasets  11  or  12 , which were the starting point, in the database  10  for producing the stimuli. After an initial phase of adjustment of the descending branch to set the loop with unity gain, and, having built up a said database  10 , the second plurality P 2  of datasets  11 ,  12  of which have been deemed sufficient, only the descending branch is subsequently exploited in order to emulate virtual movements. We may in particular think of video games, where the player&#39;s brain could perceive sensations of movement that would be purely virtual. In this case, the coupling support  3  would no longer be a corset for immobilising a limb, and it would only retain its holding function of keeping all the vibrators  61  at a predetermined position for coupling at any desired position on the body. 
     An important point to note is that, having memorized the first plurality of elementary signals P 1 , the majority in multiple copies distributed in the various, P 2 , datasets  11 ,  12  for P 2  movements actually observed, we now have a “pool” or library of elementary components of movement, so that we can foresee to increase, in memory  30 , the size of the second plurality P 2  of macro-patterns  31 ,  32  and others, that is to say to build the number up to a second larger plurality P 2 A, by adding new macro-patterns  38 ,  39  capable of causing the emulation of virtual movements, which were never observed while database  10  was being formed. The above virtual movements may be “conventional”, natural movements, such as movement of a limb or be movements which are out of the ordinary, for example corresponding to a supernatural force or extra-natural such as hallucination-like or corresponding to an unusual position, such a position adopted during a swimming exercise or a skydive from a plane. We thus can emulate the movements desired in a video game. The fine tuning needed to define each supplementary macro-pattern  38 ,  39  may be achieved through iterative trial, by applying the extra macro-pattern  38  or  39  to a subject and collecting the opinion of the person concerned about the feelings he or she perceives. 
     Datasets  11  and  12  each represents variations over time of the corresponding signals, that is to say their instantaneous amplitude constituting a temporal pattern for control of the vibrators  61 , through the transducers  51 . The waveform reflecting how instantaneous amplitude evolves over time, can be defined in memory  30  by a series of samples evenly spaced over time, for example every 5 milliseconds, equivalent to 200 Hz. Another way to represent the shape of the signal for a pattern is to consider that it has a DC component, which can vary at a certain speed, which is superimposed on an AC component, that is to say, to of faster varying amplitude and with an instantaneous frequency that can change, possibly with phase drift. We can then define the signal by data specifying how the DC and AC components of the pattern change over time. The signals generated by the tendons  2  are thus coded to be exploited digitally. Macro-patterns  31 ,  32  will each be established from the dataset  11  or  12 , their source, with intermediate transcoding, by the transcoder  20 , for adapting them to the specific characteristics of the vibrators  61 , that is to say, their sensitivity or mechanical response to electrical commands, and in particular their frequency operating range and response curve, or sensitivity, depending on frequency, just like their response phase shift with frequency. 
     In general, the parameters to take into account in the overall loop are: 
     Ascending Branch:
         Sensitivity of the reaction of tendons  2  to a movement, and this according to its magnitude, direction and speed, determining the form of the elementary bio-electric signal sent.   Sensitivity or reception in the brain.       Digitizing mode the elementary signal received in the database  10 .   

     Descending Branch:
         Transduction function of transcoder  20 .   Encoding mode in memory  30 , of signals from the transcoder  20  to form the macro-patterns  31 ,  32 .   Transformation of macro-pattern digital signals  31 ,  32  into analog signals transmitted on link  49 .   Sensitivity of the transducers  51 , in amplitude, frequency and phase.   Response sensitivity of the vibrators  61 , as regards amplitude, frequency and phase.   Efficiency of the coupling between the vibrators  61  and the area of skin facing it, and therefore with the tendon  2  under consideration.       

     The development of the invention has made it possible to identify a specific group of a said first plurality P 1  of said elementary loops, each relating to a said elementary signal and having unity gain, so as to accurately emulate a movement M 0  initially observed or even a new movement. Each macro-pattern  31 ,  32  thus comprises data specifying a modulation of amplitude and/or frequency of movement of the vibrator  61  over a predetermined period of excitation. 
     The memory  30  and associated sequencer  43  can be mechanically independent of coupling support  3 , and connected to transducers  51  by the data link  49  which may include a bundle of a first plurality P 1  of conductors each controlling a particular transducer  51 . It can however be provided for data link type  49  to be a wireless link, for example a radio link. In such cases, preferably, a common channel for data transmission on a carrier frequency is established, and the third plurality P 3  of signals in each macro-pattern  31 ,  32  is transmitted by time-division multiplexing, that is to say in the form of successive data messages sent each to a particular transducer  51  by a multiplexer  44 . Upon reception in the orthesis  3 , the messages are delivered to the intended destination above ( 51 ) through a demultiplexer  54 , acting as a channel selector or router able to reach the desired transducer from among the P 1  transducers  51  which are possible recipients. If the signals received are digital, a digital/analog converter is associated with demultiplexer  54  to convert them into analog signals suitable for directly controlling the transducers  51 . Transmission of the P 3  patterns of each of the P 2  macro-patterns  31 ,  32  may however also be done in a purely analog fashion, with an appropriate decoder at the input to link  49 . It may also be provided to store the macro-patterns  31 ,  32  in analog form. 
     In particular it may be provided for the memory  30  containing the macro-patterns  31 ,  32  and the sequencer  43  to be housed in a remote server capable of serving a whole population of orthesis  3  of so-equipped vibrators  61 . In such cases, the connection  49  is of a wireline or radio, cellular or satellite telephone type, and the transducers  51  are then controlled by telephone station circuits, for example cellular. Specifically, it can be provided for the orthesis  3  to include to a sort of pouch for attaching such a mobile station and the data port that such station conventionally includes is used for restituting, on physical signal lines, the signals for the macro-pattern  31 ,  32  received by radio. The above explanation regarding demultiplexing also applies to this case. 
     It can be conceived that such an organization for data transmission from a central server allows offering any desired changes in the variety of P 2  macro-patterns  31 ,  32 , to increase the size of P 2 . In the case of an application to a video game, one can offer a games service in real time, on demand, that is to say, after request to the server. Provision can also be made for the mobile station to receive and store the entire contents of the memory  30  for the macro-patterns  31 ,  32 , in order to then play locally, thus without maintaining the data download telephone connection above. In another variant, it is a computer network for data transmission, such as the Internet, which replaces the telephone network. 
     For the making out of the macro-patterns  31 ,  32 , tests are performed on at least one subject,
         by applying stimuli in the form of vibrations of a first macro-pattern  31  determined in advance, for a limb ( 1 ) under consideration, simulating, virtually, a determined movement,   the subject indicates his or her perception of virtual movement thus evoked by stimuli,   and, by successive iterations, by changing the parameters of the first macro-pattern  31 , the final values of said parameters are determined corresponding to a satisfactory emulation of the real movement simulated, and   having repeated the previous cycle of steps a desired number of times to obtain the desired number of macro-patterns  31 ,  32 , the parameters of these are stored to form a table constituted by the memory  30 .       

     The above parameters thus determine the temporal shape of each temporal pattern, that is to say that each parameter can be represented, as mentioned above, by amplitude samples, possibly limited in number and supplemented by information on frequency and phase. In particular, it is determined which muscles exist in the member concerned and successive cycles continue to be implemented until a sufficient number of macro-patterns  31 ,  32  are developed in order for each of said muscles to be handled by at least one of the macro-patterns  31 ,  32 . 
     Additional indications, outlining details of the tests performed, will now be provided. The task in hand was to develop the macro-patterns  31 ,  32  and  38 ,  39 , that is to say, to determine the residual errors between the sensation of movement induced in subjects and a real movement that each macro-pattern represented as well as possible. The following abbreviations are used for tendons  2  of the ankle: TA=tibialis anterior, EHL=extensor hallucis longus, EDL=extensor digitorum longus, PL peroneus lateralis=, GS=gastroenemius soleus, TP=tibialis posterior, and  FIG. 2C  for the wrist, involves the extensor, abductor, flexor and adductor. 
     The subjects were seated on a chair, holding a pencil in the hand ( FIG. 4 ).  FIGS. 3A and 3B  show that one of their ankles was maintained at a right angle to the tibia, with P 1 =5 vibrators  61  on the tendons  2  under a pressure of about 0.5 N. In  FIG. 3C  it is a wrist which is coupled to P 1 =4 vibrators  61 . The vibrators  61  were a product marketed by IKAR Co. Ltd under the commercial name Vibralgic model. The vibrators  61  had a head 1 to 2 cm long and 1 cm in diameter. It will be recalled that a vibrator  61  may be formed of a coil powered by the electric signal for the elementary pattern, amplified to the desired power, thereby producing an alternating magnetic field of a desired instantaneous amplitude and frequency and changing with time in order to produce the precise form of the elementary pattern. Each elementary pattern consisted of a series of 5 ms pulses, with a peak-to-peak amplitude of 0.25 mm. Their spectrum was in the band ranging from 1 to 100 Hertz. The vibrator  61  may also be formed from a rotating electric motor rotor coupled to an eccentric mass. One can yet again provide a piezoelectric element.  FIG. 2A  thus shows a macro-pattern of five temporal patterns initially picked up on a subject when imposing on the ankle joint of the latter movement that matches the trace of the letter “a” through the end of the segment corresponding to this joint (dataset  11 ) and re-transcribed in macro-pattern  31  in the memory  30 , these elementary patterns cooperating to describe the neuro-sensory trace of the letter “a” through the sequencer  33  and the vibrators  61 . 
     In the case of  FIGS. 2B-2C  and  3 B- 3 C, we are dealing with a synthesis approach, in which a suitable set of elementary patterns was developed, that is to say that we chose those tendons  2  that it was appropriate to excite, and it was determined again, without the use of the experimental observations, what the temporal shape of each elementary pattern signals needed to be in order for the subject to best perceive a path determined as “correct” that is to say reproduces it, this respectively for the excitation of the ankle ( FIG. 4B ) or wrist ( FIG. 4C ).  FIG. 4B  shows how it was possible to improve the natural signals ( FIG. 2A ) in order to obtain a perfect trace of the letter “a”, thus indicating the desired perception to achieve this result. This is consequently a correction of a distortion of perception shown in  FIG. 4A . The transcoder  20  can thus perform the inverse correction of the above distortion. 
       FIG. 5  shows a top view of the foot, with various vectors representing the various excitations TA+EHL, EDL, PL, GS and TP in  FIG. 2 . To develop an artificial or synthetic macro-pattern  38 ,  39 , a low pass filter was used to smooth the recordings of the paths followed. Moreover, the components of angular velocity of the path for writing the letter or digit in question, as orthogonal coordinates on the x-axis and y-axis were determined To do this, we determine, at eight fixed rate, every 200 ms, the difference in positions            x and          y of a current point in the writing path on the two axes, which supplied the direction and magnitude of an instantaneous velocity vector. A comparison between two such successive vectors then supplies an angle of deflection of the trajectory, having a bijective relationship with a certain curvature. According to this, the velocity vectors show progressive changes in their norm and therefore the structure of the artificial patterns is changing in the same way.
     It is therefore designed for the ankle to receive various vectorial vibrations and therefore detect any change in direction of at least one of these. Regarding the sensitivity of such detection, we can define for each muscle, a direction of maximum sensitivity, that is to say that a given vibration will be perceived as attenuated if it has an oblique direction relative to the direction of maximum sensitivity. If we move away angularly from the direction of maximum sensitivity, the excitation of the vibrators  61  should be multiplied by the cosine of the angle of obliquity then existing. Such a method for drawing up macro-pattern for synthesis excitation of vibrators is applicable to any joint in the body of a living being. 
       FIGS. 6 and 7 , similar to  FIG. 2 , each show five signals for the elementary pattern of five tendons  2 , respectively for the letter “a” and the digit  8 . For each elementary signal, it is shown, over 6.5 seconds, variations in signal frequency versus time, this frequency being normalized between 0 and 1, between the said lower limit of 1 Hz and the upper limit of 100 Hz. Each signal is in fact shown twice, firstly as a natural, experimental pattern (dashed line) determined from results obtained on the subject, and, additionally, as an artificial pattern (solid line), that is to say, generated while developing an artificial macro-pattern  38  or  39 . The differences observed between the two signals of each pair are minor, that is to say they are not significant. 
       FIG. 8A  shows eight paths with trajectories imposed for the four digits  1 ,  2 ,  3 ,  8  and the four letters a, b, e, n.  FIG. 8B  shows the corresponding traces reproduced experimentally as discussed in relation with  FIGS. 2A ,  3 A and  4 A, while  FIGS. 8C and 8D  correspond to the conditions discussed respectively in relation with  FIGS. 2B ,  3 B,  4 B and  2 C,  3 C,  4 C, that is to say for the ankle or wrist.