EP2271298A1

EP2271298A1 - Appliance for generating sensations of movement and for functional reeducation

Info

Publication number: EP2271298A1
Application number: EP09733967A
Authority: EP
Inventors: Jean-Pierre Roll
Original assignee: Centre National de la Recherche Scientifique CNRS; Universite de Provence Aix Marseille I
Current assignee: Aix Marseille Universite; Centre National de la Recherche Scientifique CNRS
Priority date: 2008-04-22
Filing date: 2009-04-22
Publication date: 2011-01-12
Also published as: WO2009130579A1; CA2722025A1; US8956312B2; US20110034253A1; FR2930139A1; FR2930139B1

Abstract

The appliance designed to allow a living being to perceive sensations of virtual movements of part of his body (1) comprises a control unit (30, 40, 41, 42, 43) in which is stored a table (30) containing a first plurality (P1) of basic excitation signals, a second plurality (P2) of macro-motifs (31, 32) each formed by a third plurality proper (P3) of said basic signals, a sequencer (43) reading the macro-motifs (31, 32) in order to emit a second plurality (P2) of corresponding commands for excitation, each time, of a third plurality proper (P3) of vibrators (61) selected from among a first plurality (P1) of vibrators (61) carried by a coupling support (3) in predetermined respective zones of the part of the body (1), the excitation of the third plurality proper (P3) of vibrators (61) by the second plurality (P2) 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

DEVICE FOR GENERATING MOTION SENSATIONS AND FUNCTIONAL REEDUCATION

The present invention relates to a device capable of generating sensations as perceived by the brain during the execution of a movement affecting a part, or all, of the body of a subject, whereas this same part of the body body is not affected by any movement.

The present invention relates, inter alia, to the functional rehabilitation of persons, or even certain animals, of which a damaged limb, or any other part of the body, is immobilized by a corset.

The present invention also relates to education and functional rehabilitation relating to movements that the brain can no longer perform, or performs only imperfectly, following an injury, accidental or resulting from an illness, or because of a malformation. The present invention also relates to the learning, by an individual or an animal, of a gesture, or movement having a specific purpose. It also relates to the addition to the perception received, by an individual or an animal, of a situation or a virtual event, of a type of additional sensory information. It is customary to call such a confrontation of a subject with images, sounds and any other type of sensory information a descriptive representation of the situation or virtual event. The present invention is capable of causing a subject to perceive the sensations corresponding to movements, whether or not the subject executes these movements, which constitutes in fact additional sensory information for the perception of virtual reality, and therefore enrichment. from this perception.

A person with a fracture of a lower or upper limb, or a ligament injury, is usually provided with a rigid brace that immobilizes the affected portion of the limb, such as a joint. When the brace is removed, after a few weeks, the muscles of the joint are unable to ensure the movements they allowed before the immobilization of the joint. This is due, on the one hand, to the fact that the muscles have been injured or not used and, on the other hand, to the fact that the brain has lost some of its ability to handle the movements resulting from the stresses of these muscles. Indeed, many studies have shown that some brain networks, assigned to this task, are gradually reassigned to other tasks if they do not receive the nerve messages that emit the skin and muscles when they work. Physiological receptors located particularly in the skin, and in the muscles, are responsible for transmitting bioelectrical messages to the brain. In particular, some of these receptors are between the muscle fibers, and are arranged in such a way that they are sensitive to muscle extension. These messages are "reports" that describe the detailed movement of each muscle, so that the brain can, in turn, represent an action and control the muscles to eventually correct their movement and also to guide the continuation of movement in the desired direction.

Writing is a good example of such a servo loop. The person writing will simultaneously contract or lengthen a number of muscles of the hand and wrist, all of these elementary movements in front of, obviously, be perfectly coordinated. In particular, the brain captures the messages emitted by each involved muscle and the skin, in case of extension, and it synthesizes this information to determine what, until then, the movement has been done, that is, say the plot, in the case of writing.

The present invention aims in particular to reduce the need for functional rehabilitation when part of the body of a living being, in particular a human being, has been immobilized. It may also allow for the correction of impairment or inability to perform movements, whether resulting from an injury or malformation, motor or nervous system.

For this purpose, the invention firstly relates to a device, in particular for the functional rehabilitation of a body part of a living being, comprising a control unit comprising in memory a table containing a first plurality of elementary signals. excitation circuit serving as constituent elements of a second plurality of macro-patterns each consisting of a third own plurality of said elementary signals, the control unit comprising a sequencer arranged to read the macro-patterns and to emit a said second plurality corresponding commands of excitation, each time, a said third plurality of own vibrators selected one of said first plurality of vibrators carried by a coupling support in respective predetermined areas of the body portion.

Each macro-pattern consists of a set of elementary patterns which each represent the shape of a signal controlling the movement of one of the vibrators, ie a mechanical exciter of a point of the skin and / or any physiological receptor element located below, such as for example a tendon or a muscle. The macro-motifs are determined from recordings previously made in human subjects or are macro-patterns of synthesis, established by composition of elementary patterns, the shape of each of which has 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 linked to a damaged joint, this stimulation being carried out in a direction, a intensity and a frequency which constitute as many parameters in the choice of each memorized elementary pattern. The variation over time of this stimulation, and the multiplication of the points of stimulation constitute as much stimulation of the physiological receptors. It is therefore the spatio-temporal combination of these simultaneous stimuli, that is to say, applied at various points on the skin to excite the tissue beneath, which will supply the brain, at any moment, with a set of data of the type "neurosensory flow", that is to say that the brain receives the sensory messages from the various excited tissues that depend on the amplitude and frequency of the various vibrations, which will constitute an emulation of the effective elongation immobilized muscle, stretching of the skin and perceived displacement of the limb. The neural networks of the relevant areas of the brain will thus regularly receive such information, at the rate set by the sequencer, and the maintenance thus assured of the corresponding processing task will ensure that these networks will remain, at least to a large extent, assigned to the processing of the flows. from the muscles considered, since immobilization of these muscles will be masked.

After healing of the muscle or the joint and thus release of it, the reeducation will be essentially only mechanical, that is to say will be almost exclusively on the recovery of the total force of the muscle, since the brain will have preserved the corresponding network of representation and movement management. As mentioned above, each macro-pattern may comprise data specifying a modulation of amplitude and / or frequency of the movement of the vibrator over a predetermined excitation period.

Advantageously, the sequencer is mechanically independent of the coupling medium, and is connected to the vibrators by a data link. The vibrators are for example controlled through a respective transponder.

It is thus possible to equip an injured person with a sort of harness holding the vibrators at the desired place, the problem of immobilization being treated by a sleeve or other element external to the device according to the invention. In general, the only elements necessarily worn by the patient are the vibrators with their coupling support. On the other hand, the macro-patterns can perfectly be stored in a server common to several such devices. The common server can therefore contain a complete library of all types of macro-patterns, that is to say for all types of members or other that may be treated. For a treatment of a given limb, the sequencer will therefore choose the appropriate set of macro-patterns.

The supply link of the macro-patterns to the vibrators can be provided by cellular telephone circuits or links with a data transmission network. It will be recalled that a mobile phone has a data exchange port which, in this example, can be connected to a logic of data exchange management and control of vibrators. One can also think of an Internet-type connection, preferably with a wireless terminal link, that is to say of the WiFi type or equivalent, to permanently maintain the ambulatory aspect. A person in ambulatory medicine at home, for example, can receive data messages containing the desired sequences of macro-patterns. The above management logic, forming a sequencer and a local adapter of format and bit rate transmitted, will then store the data bits representing the sequences of macro-patterns received at high speed by the network, and restore, in Delayed time, these data in a format wanted compatible with the vibrators, and at the desired speed. The device according to the invention and described above, can be provided to limit the need for functional rehabilitation after immobilization of all or part of the body, for example following a fracture, injury or pathology. It can also be provided to reduce the consequences of prolonged bed rest, by maintaining in activity the neural circuits for processing basic descriptive movement messages, for example the maintenance in natural posture or locomotion.

Moreover, it has been found that the implementation of the device according to the invention made on a subject so as to provide its brain with the descriptive messages of the same movement in a repetitive manner is capable of gradually inducing the execution by the subject of the said movement. This property can be used to enrich or correct the repertoire of gestural knowledge recorded by the brain, and to realize the learning of an unknown gesture, or the perfecting of an imperfectly performed gesture. The device according to the invention can thus be provided as a means of functional rehabilitation by providing the brain with descriptive messages of a movement that this brain does not know or no longer knows how to execute, or performs only imperfectly. Such situations may result from injury due to illness or accident, or from malformation. These neurological lesions, accidental or degenerative, can affect the central or peripheral nervous system. This device can in particular be adapted to deliver the descriptive messages of the movements corresponding to the locomotion. In this particular case, the interested muscles having been identified, the vibrators are held in appropriate position by a suitable coupling support, to transmit stimuli to the appropriate physiological receptors according to the excitation signals provided by the reading of the specific macromotifs of the walking . Another application of the device according to the invention is constituted by the rehabilitation to maintain a posture, or particular attitude of the body of a living being, for example the standing of the human being.

The device according to the invention can also be provided to allow the learning or development of complex gestures, including requiring precision. Examples include writing, gestures related to sports activities, service to tennis or golf swing, professional or artistic activity. Such learning or development may also apply to the performance of gestures in conditions different from the usual conditions of a subject. These include the conditions corresponding to free fall, microgravity or weightlessness, increased gravity and acceleration. Such a device can also be used in the context of virtual reality. Indeed, the mobilization of the largest number of sensory channels contributes to improving the quality of the perception of the virtual reality felt by the subject, human or animal. At the usual channels that are the view, solicited by the image, the hearing by the sound, and sometimes the touch through various mechanical devices, the device according to the invention can be used to add sensations of movement, and thus enrich the description of the situation corresponding to the virtual reality to which the subject is confronted.

The device according to the invention can be provided to be an integral part of a virtual reality production system. These systems include video game consoles and simulators of all kinds. These include flight simulators, driving all kinds of machines, industrial process control, simulators of extreme conditions, such as weightlessness and ultra-gravity, simulators of complex gestures and precision. such as surgery. The system for producing virtual representations comprising a device according to the invention which is functionally integrated with it, associates sensations of the sensory channels of the user with sensations of perception of virtual movements. Indeed, this system will then provide the brain with sensory information messages corresponding to body movements represented by the virtual reality produced by the system, and to which the subject is confronted, giving the impression of the execution of these movements. whether or not this subject executes the said movements. This result is obtained through a recording and analysis of the movements which one wants to give the impression of execution, and an identification of the muscles put in play by these. The specific macromotifs of each of the movements are used to control, whenever such a movement results from the virtual situation represented, the vibrators held in appropriate manner so that they stimulate, when they are stressed, the tendons of the muscles concerned. by this movement.

The device according to the invention comprises means for holding the vibrators in contact with the skin, at the desired location, or coupling support. It is possible to adopt many embodiments to provide the function of this coupling support, which closely depend on the use made of the device. Achievements may take the form of a harness, a combination, a partial or total garment, whose material and design details are suitable for use. A harness may for example take the form of a set of straps with means of adjustments for adjusting the position of the vibrators, and the characteristics of the contact of each vibrator on the skin. In addition, the coupling support can fulfill one or more other functionalities that have a synergy with the particular use made of the device according to the invention. In particular, the coupling support may functionally provide the contention or the immobilization of a part of the body corresponding at least in part with the part subjected to the stimuli.

The invention therefore relates more generally to a device for generating bioelectric signals, providing a living being sensations corresponding to the execution of a given movement of a part of his body (1) even if this movement is not executed, comprising:

a table of elementary excitation signals,

a control unit comprising a sequencer,

vibrators carried by a coupling support holding each of them in a predetermined position relative to body elements of the part of the body, in which, for each given movement, each vibrator can receive an elementary excitation signal so that it mechanically stimulates body elements of the body part to cause the emission of bioelectric signals, the set of elementary excitation signals of the various vibrators constituting a macro-pattern, these elementary signals being chosen to constitute a macro-pattern specific characteristic of the movement considered, this macro-pattern read by the sequencer giving the vibrators elementary excitation signals capable of causing the creation of bioelectric signals in the living being making him perceive the sensations of execution of said movement. The invention also relates to a method for establishing the excitation macro-patterns of the device according to the invention, in which method tests are carried out on at least one subject person,

by applying to it stimuli in the form of vibrations of a first macro-pattern determined a priori, for a part of the body considered, simulating, virtually, a determined movement,

- the subject indicates the perception that he has of the virtual movement thus evoked by the stimuli,

and, by successive iterations, by changing parameters of the first macromotif, final values of said parameters corresponding to a satisfactory emulation of the simulated real movement are determined, and

- Having repeated the cycle of previous steps a desired number of times to obtain the desired number of macro-patterns, one memorizes the parameters thereof in said table.

In particular, it is possible to determine which muscles exist in the part of the body considered and the execution of the successive cycles is continued until a sufficient number of macro-motifs have been developed so that each of the said muscles is treated with at least one of the one of the macro-patterns.

The invention also relates to a use of the device according to the invention, in which the device is functionally integrated with a video game console to emulate, at the level of a user, movements of an avatar of the latter represented on a video game console. screen.

The user can thus perceive the movements of his avatar and possibly the voluntary movements that the user executes or the shocks he receives. In a sophisticated form of use, the user manipulates a tri-directional accelerometer (3D) to control the movements of his avatar, that is to say he controls the game by his own 3D movement, in direction and intensity, and that it perceives it or only its contact with the environment (shock against a wall, boxing fight) by means of the device according to the invention. His perception of events presented on the screen is therefore both visual and tactile and motor, with sensations of local acceleration, that is to say movement. It is therefore conceivable that these two parallel and complementary channels of perception of the environment make it possible to immerse the user intensely in this increased visual environment. More generally, the invention relates to devices and methods as defined in the claims.

The invention will be better understood with the aid of the following description of an embodiment of an orthesis embodying the method of the invention, with reference to the appended drawing, in which:

FIG. 1 is formed of a figure IA, which is a block diagram illustrating the context of the invention, in the form of an information transmission loop between a tendon associated with the orthosis and the brain, and a FIG. 1B, which illustrates more precisely the shape of the orthosis; FIG. 2, formed of FIGS. 2A, 2B and 2C, shows three examples of time signals representing the letter "a",

FIG. 3, formed of FIGS. 3A, 3B and 3C, represents a considered articulation of a subject for FIG. 2A to 2C respectively,

FIG. 4, formed of FIGS. 4A, 4B and 4C, represents the manual writing of the letter "a" above, corresponding to FIGS. 3A to 3C respectively,

FIG. 5 represents a foot associated with various directions of sensation, evoked by the vibration of various tendons,

FIGS. 6 and 7 each represent five temporal patterns of signals coming from various muscles, when the letter "a" and the number 8 respectively are drawn respectively, with each time a natural signal picked up and the same signal after treatment, and

FIG. 8, consisting of FIGS. 8A, 8B, 8C and 8D, respectively comprises four lines of four identical digits and four same basic letters, illustrating the perception that is acquired when applying macro-patterns.

Figure IA is a schematic view illustrating the context of the invention. The muscles of the moving foot 1 of a person, here seen from the right, and precisely tendons 2, classically transmit to the brain significant elementary signals of the movement in progress, that is to say the trajectory and speed of the foot 1, in the form of its global movement in advance as well as its movements in rotation. Figure 1B shows, in left view, in more detail the shape of the orthosis, which closely wraps the foot and the bottom of the calf.

It will be recalled that, in a conventional manner, the movement of any object can be defined by referring to six types of movement, namely three translations according to respectively three orthogonal axes, such as for example a vertical axis and two horizontal axes defining a forward / backward direction and a lateral direction, and three orthogonal axes of rotation.

The movement was provoked by a voluntary command of the brain or by a reflex action. The signals received in return by the brain are thus a report of the movement executed, so that the brain can send a correction order if necessary, to rectify a movement that it deems incorrect or to chain a continuation of the movement. This is especially important for synchronizing walking.

The brain is thus used to dealing with this kind of signals. However, in case of immobilization of the limb, following a sprain, fracture or other, the brain no longer receives such signals and the neural networks that treated them are gradually assigned to other tasks.

Such "motion" elementary signals received by the brain have been captured by electrodes inserted into the nerve, close to the sensory fibers from the physiological receptors, and recorded in a database 10. The total number of tendons 2 thus defines a first plurality, of size Pl, of such elementary signals, and any particular movement MO, out of a second plurality P2 of possible motions, corresponds to a specific subset constituting a particular set consisting of a third plurality P3 of elementary signals belonging to to the first plurality Pl. Each third plurality P3 is therefore of size specific to the motion MO considered of the second plurality P2, since it is composed of those of the elementary signals which are specific to this movement MO.

In the present description, the plurality references P1, P2 or P3, which each relate to different types of elements, designate only the number or size of the plurality, whereas the nature or type of the elements is indicated by the terms associated with the reference.

As a purely numerical explanation, there is for example a first plurality Pl of 5 tendons 2 to be monitored (only two tendons 2 being represented), that is to say a first plurality Pl of elementary signals to be acquired through 5 acquisition channels. A first determined movement Ml, among the second plurality P2 of movements, for example representing 10 MO motions, will cause for example a reaction on a said third plurality P3 of channels which will be example consisting of the channels of rank 1 to 4, while a second movement M2 will cause a reaction on another third plurality P3 of channels constituted by the channels of rank 3 to 5. It is thus seen that the third pluralities P3 of channels, and therefore also of elementary signals, are of disparate sizes, here of respective sizes 4 and 3 channels. Each of the third plurality P3 of elementary signals P3 thus forms a block of data, of size P3 (number of elementary signals) specific to the MO motion considered. The second plurality P2 of movements may be much larger than the first plurality Pl of elementary signals since the various (P3) data blocks of the second plurality P2 of movements are each formed by specific combinations and sizes P3 mutually different, said elementary signals taken from the first plurality Pl.

In order to mutually identify these elementary signals, it has been defined, during tests, a first set of typical movements, in number of relevant signals constituting the first plurality Pl. For each movement MO, that is to say each third plurality P3 of elementary signals, it has been established an average of each of the elementary signals, that is to say a smoothing of the deviations due to various causes, such as the size or morphology of the subject.

The references 11 and 12 thus designate, each for a particular MO motion among the P2 motions, a said data block containing a third plurality P3 of such elementary signals, the two blocks 11, 12 respectively corresponding to two standard or "standardized" movements. ", Ml and M2, determining the size of the second plurality P2, which is therefore P2 = 2, to simplify the present disclosure. Of course, this is a simplified representation because a much larger second plurality P2 of blocks containing a third plurality P3 of MO motion signals has been established. Each third plurality P3 of signals of a block 11 or 12 thus represents all the elementary signals emitted by various tendons 2 during the movement MO considered. As indicated, the various third pluralities P3 are in general of respective different sizes, that is to say that each movement MO involves a number of tendons 2 that are specific to it, for example each time from three to five out of one plus one. large number (P1) of existing tendons 2, but whose other tendons 2 are not of interest for the MO motion considered. In short, this ascending branch, towards the brain, implements a transducer function, passing from the domain of mechanics, and more precisely of kinematics, that is to say a domain of "action", in the field of bio-electricity in which are the signals, and more precisely the domain of the information or knowledge, with the analysis of the signals by the brain.

A fundamental idea was to examine whether the inverse transformation could be performed from the database 10 which is a descriptive library of the bioelectric responses to the various (P2) MO motions.

The interest is to be able to cause the creation of these same second pluralities P2 of each P3 signals, sensory feedback to the brain, when the part of the body considered, so here the foot 1, is immobilized by a coupling support 3 here under sensory feedback orthosis form constituting a corset applied to the foot 1, injured, so as to maintain the corresponding analysis activity in the brain.

To do this, a downward leg 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 electromechanical type to transform the electrical control signals into mechanical stimuli. at the level of the tendons 2. The database 10 thus controls a transcoder 20 which itself writes a memory 30 of a said second plurality P2 of macro-patterns 31, 32, each containing a said third plurality P3 of signals elementary, the macro-patterns 31, 32 being defined bijectively from the respective data blocks 11 and 12 specific to each movement MO.

The memory 30 belongs to a control unit 40 managed by a central unit 42 driven by a time base 41 and associated with a sequencer 43 read-connected to the macro-pattern memory 30. Each macro-pattern, among the second plurality P2 of macro-patterns 31, 32 each containing P3 electronic control patterns, can thus control, by a link 49 comprising a said first plurality Pl of channels, a said third plurality P3, which is specific, transducers 51, or transponders , chosen from among a first plurality Pl of transducers 51. The first plurality Pl of transducers 51 controls a said first plurality Pl of associated respective vibrators 61 applied at various predetermined positions to the muscles of foot 1 and in particular to respective pl tendons 2 . In other words, the cutting in first P1, second P2 and third P3 pluralities of this downstream section of the descending branch, electronic and mechanical, is the image of what exists on the rising branch, body. FIG. 1B shows that the vibrators 61 are housed under the envelope constituting the orthosis and applied to the associated tendon 2 under a pressure set by a coupling adjustment screw 61V.

The first plurality Pl of pairs of transducers 51 and vibrators 61 is therefore of sufficient size to make it possible to cause all the types of elementary signals of the database 10. However, it will be noted that there may be even more transducers 51 and vibrators 61, that is to say a fourth plurality of larger size than the first plurality Pl, if, for example, it is expected to combine the vibrations of several vibrators 61 to obtain a vibratory composition in an optimal composite direction, representing the direction of maximum sensitivity of a tendon 2, that is to say for which it provides, in response to the brain, an elementary signal of maximum amplitude. Specifically, the macro-pattern 31 or 32 which is selected, in order to emulate, vis-à-vis the brain, a movement Ml or M2 among the second plurality P2, will control one of the second pluralities P2, among the first plurality Pl transducers 51, to mechanically stimulate those tendons 2, or other body elements, which normally generate the elementary electrical signals in response to the actual motion M1 or M2 considered.

In terms of the slave system, the loop constituted by the rising branch, tendons 2 to the database 10, and the descending branch, return, presents a unit gain, that is to say that the descending branch is capable of to produce, and to deliver on the tendons 2, signals of a mechanical nature which cause in reaction the creation of biological elementary electrical signals and, moreover, the descending branch is arranged so that the elementary electrical signals, which it induces by reaction of tendons 2, are substantially identical to the original elementary signals, that is to say those which, after numerical coding, form the blocks 11 or 12 from which one started, in the database 10, for produce the stimuli. After an initial phase of focusing of the descending branch to adjust the loop to unity gain, and, having constituted a said database 10, the second plurality P2 of blocks 11, 12 will have been judged sufficient, it is then not exploited that the descending branch to emulate virtual movements. One can in particular think of games on video console, in which the brain of the player would perceive sensations of movements which would be only purely virtual. The coupling support 3 would no longer be a limb immobilization corset, and it would retain only its holding function, to keep all the vibrators 61 in the predetermined coupling position at any desired body location.

An important point to note is that, having memorized the first plurality Pl of elementary signals, most of them in several copies distributed in the various P2 data blocks 11, 12 of P2 movements actually observed, there is thus a "pool" or library of elementary constituents of movement, so that it can be expected to increase, in the memory 30, the size of the second plurality P2 of macro-patterns 31, 32 and others, that is to say to mount to a second increased plurality P2A, by adding new macro-patterns 38, 39 able to cause the emulation of virtual movements, which have therefore never been observed to constitute the database 10. The virtual movements below above can be "classical" movements, natural, such as a movement of a limb, or be out of the ordinary movements, for example corresponding to a supernatural or extranatural force such as hallucination or still corresponds to an unusual position, for example a position adopted during a swimming exercise or a free fall jump from an airplane. We can thus emulate the desired movements in a video game. The focus necessary to define each additional macro-pattern 38, 39 can be performed by iterative tests, by applying the additional macro-pattern 38 or 39 to a subject and collecting the opinion of the person concerned as to the sensations that she perceives.

The data blocks 11 and 12 each represent the time evolution of the corresponding signals, that is to say their instantaneous amplitude constituting a temporal pattern of control of the vibrators 61, through the transducers 51. The shape of the signal, representing the evolution of this instantaneous amplitude over time can be defined, in memory 30, by a series of regularly spaced samples temporally, for example every 5 milliseconds, therefore at 200 Hz. Another way of representing the shape of the signal of a pattern is to consider that it comprises a continuous component, capable of varying at a certain speed, on which is superimposed an alternating component, that is to say of varying amplitude. faster and according to an instantaneous frequency that can vary, possibly with phase drifts. The signal can then be defined by data specifying the evolution of the continuous and alternative components of the pattern. The signals generated by the tendons 2 are thus coded so that they can be used digitally.

The macro-patterns 31, 32 will each be established from the source block 11 or 12, with an intermediate transcoding, by the transcoder 20, to adapt them to the specific characteristics of the vibrators 61, that is to say their sensitivity. , or mechanical response to electrical controls, and in particular their frequency operating range and their response curve, or sensitivity, according to the frequencies, as well as their response phase shift according to the frequency.

In a general way, the parameters to be taken into account in the global loop are the following ones:

Rising branch:

Sensitivity of the reaction of the tendons 2 to a movement, and this according to its amplitude, its direction and its speed, determining the form of the elemental bio-electrical signal emitted.

- Sensitivity of reception at the level of the brain.

- Scanning mode, in the database 10, the captured elementary signal.

Branch down:

Transducer Transducer Function 20. Coding Mode, in the Memory 30, of the Signals Derived from the Transcoder 20, to Constitute the Macro-motifs 31, 32

- Transformation of the digital macro-pattern signals 31, 32 into analog signals transmitted on the link 49.

Sensitivity of response of the transducers 51, as regards the amplitude, the frequency and the phase.

- Response sensitivity of the vibrators 61, amplitude, frequency and phase. - Efficiency of the coupling between vibrators 61 and the skin area opposite, and therefore with the tendon 2 considered.

The development of the invention has made it possible to determine a beam of a said first plurality Pl of said elementary loops, each relating to a said elementary signal and having a unity gain, to thereby accurately emulate an initially observed MO motion. , even a new movement.

Each macro-pattern 31, 32 thus comprises data specifying a modulation of amplitude and / or frequency of the movement of the vibrator 61 over a predetermined excitation period. The memory 30 and the associated sequencer 43 may be mechanically independent of the coupling support 3, and connected to the transducers 51 by a said data link 49 which may comprise a beam of a first plurality Pl of wires each controlling a particular transducer 51. However, it may be provided that the data link 49 is of the wireless type, for example radio. In such a case, it is preferably established a common data transmission channel, on a carrier frequency, and the third plurality P3 of signals in each macro-pattern 31, 32 is transmitted by time division multiplexing, i.e. in the form of successive data messages each addressed to a particular transducer 51 by a multiplexer 44. In reception in the orthosis 3, the messages are distributed to the above recipient (51) by a demultiplexer 54, that is to say say a switcher able to join the wanted one among the transducers 51 possible recipients. If the signals thus received are digital, a digital / analog decoder is associated with the demultiplexer 54 to transform them into analogue signals able to directly control the transducers 51. The transmission of the P3 motifs of each of the macro macro-patterns 31, 32 can, however, also be carried out in a purely analog way, with such a decoder input of the link 49. It can also be expected to store the macro-patterns 31, 32 in analog form.

It may in particular be provided that the macro-pattern memory 31, 32 and the sequencer 43 are housed in a remote server, able to serve a whole population of orthoses 3 thus equipped with vibrators 61. In such a case, the link 49 is for example wired telephone type or radio, cellular or satellite, and the transducers 51 are then controlled by telephone circuits, for example cellular. Specifically, it may be provided that the orthosis 3 comprises a kind of case for fixing such a portable station, and the conventional port of data that usually has such a station is used to restore, at the wire level, the macro signals. reason 31, 32 received by radio. The above explanation on demultiplexing is also valid in this case. It is conceivable that such an organization for transmitting data from a central server makes it possible to offer any desired evolution in the variety of macromotive P2s 31, 32, to increase the size of P2. In the case of an application to a video game, it is thus possible to offer a game service in real time, on demand, that is to say after request from the server. It is also possible for the portable station to receive and store all the contents of the macro-pattern memory 31, 32, and then play locally, thus without maintaining the data download telephone link above. In another variant, it is a computer network for data transmission, for example the Internet network, which replaces the telephone network.

For the establishment of the macro-motifs 31, 32, tests are carried out on at least one subject person,

by applying to it stimuli in the form of vibrations of a first macro-pattern 31 determined a priori, for a member (1) considered, simulating, virtually, a determined movement,

the subject indicates the perception he has of the virtual movement thus evoked by the stimuli, and, by successive iterations, by changing the parameters of the first macromotif 31, final values of the said parameters corresponding to a satisfactory emulation of the simulated real motion, and

having repeated the cycle of preceding steps a desired number of times to obtain the desired number of macro-patterns 31, 32, the parameters thereof are memorized to form a table formed by the memory 30.

The above parameters therefore determine the temporal form of each temporal pattern, that is to say that each parameter can be represented, as mentioned above, by amplitude samples, possibly in limited numbers and supplemented by information frequency and phase. In particular, we determine what are the existing muscles in the member considered and we continue the execution of successive cycles until we have developed a sufficient number of macro-motifs 31, 32 for each of said muscles to be processed by at least one of the macro-motifs 31, 32.

Additional indications, detailing the tests carried out, will now be provided. It was a question of developing the macro-motifs 31, 32 and 38, 39, that is to say of determining residual errors between the sensation of movement induced in subjects and a real movement that each macro-motive represented as well as possible.

The abstracts used for ankle tendons 2 are TA = tibialis anterior, EHL = extensor hallucis longus, EDL = extensor digitorum longus, PL = peroneus lateralis, GS = gastroenemius soleus, TP = tibialis posterior, and FIG. wrist, concerns the extensor, abductor, flexor and adductor.

The subjects were seated in a chair, holding a pencil in hand (Figure 4). Figures 3A and 3B show that one of their ankles was held at right angles to the tibia, with Pl = 5 vibrators 61 on the tendons 2, at a pressure of about 0.5 N. In FIG. 3C, FIG. is a wrist which is thus coupled to P1 = 4 vibrators 61. The vibrators 61 were a product marketed by the company IKAR Co. Ltd, under the protected 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 consist of an electric winding powered by the elementary pattern signal, amplified to the desired power, thereby producing an alternating magnetic field of desired instantaneous amplitude and frequency and evolving to produce the precise shape elementary pattern. Each elemental pattern consisted of a sequence of 5 ms pulses, with a peak to peak amplitude of 0.25 mm. The spectrum was in the band from 1 to 100 Hertz. The vibrator 61 may also be constituted from a rotary electric motor rotor coupled to an eccentric mass. One can still provide a piezoelectric element.

FIG. 2A thus shows a macro-pattern of five temporal patterns initially captured on a subject when it imposes on the articulation of the ankle thereof a movement which corresponds to the trace of the letter "a" by the end of the segment corresponding to this articulation (block 11), and retranscribed 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 3B-3C, this is a synthetic approach in which the appropriate set of elementary patterns has been developed, i.e. tendons 2 were chosen which are suitable for excitation, and the temporal form of each of the elementary pattern signals was determined again, without resorting to their experimental observations, so that the subject perceives at best a determined "correct" pattern, c ie, reproduce it, for the excitation of the ankle (FIG. 4B) or wrist (FIG. 4C) respectively. FIG. 4B thus shows that the natural signals (FIG. 2A) have been improved to obtain a perfect trace of the letter "a", thus indicating the perception required to obtain this result. It is therefore a correction of a perception distortion visible in FIG. 4A. Transcoder 20 can thus perform the reverse correction of the above distortion.

FIG. 5 represents a foot in a view from above, with various vectors representing the excitations TA + EHL, EDL, PL, GS and TP of FIG. 2.

To develop an artificial or synthetic macro-pattern 38, 39, a low-pass filter has smoothed the recordings of the trajectories executed. Moreover, angular velocity components of the writing trajectory of the letter or number considered, in orthogonal coordinates of x-axis and y-axis, have been determined. To do this, we have, at a fixed rate, every 200 ms, determined the difference of positions ûx and ûY of a current point of writing trajectory on the two axes, which provided the direction and the size of a instantaneous speed vector. The comparison between two such successive vectors then provided an angle of deviation of the trajectory, corresponding, in a bi-univocal manner, to a certain curvature. According to this one, the velocity vectors see their norm evolve and consequently the structure of the artificial grounds evolves in the same way. It is therefore conceivable that the ankle receives the various vector vibrations and thus detects any change of direction of at least one of these. With regard to the sensitivity of such a detection, one can define, for each muscle, a direction of maximum sensitivity, that is to say that the same vibration will be perceived attenuated if it has an oblique direction by report to the direction of maximum sensitivity. If one moves angularly away from the direction of maximum sensitivity, the excitation of the vibrators 61 must be multiplied by the cosine of the angle of obliquity then existing. Such a method for producing synthetic macro-motifs of vibrators is applicable to any articulation of the body of a living being.

FIGS. 6 and 7, homologues of FIG. 2, each represent five elementary pattern signals of five tendons 2, respectively for the letter "a" and the number 8. For each of the elementary signals, it has been represented, out of 6, 5 seconds, the evolution of the frequency of the signal as a function of time, this frequency being normalized between 0 and 1, between the said lower limit 1 Hz and the upper limit 100 Hz. Each signal is in fact represented twice, all of firstly as a natural, experimental (dotted) motif, determined from a survey carried out on a subject, and also as an artificial motif (continuous line), that is to say generated during the setting at the point of an artificial macro-pattern 38 or 39. The differences that are observed between the two signals of each pair are minor, that is to say they are not significant.

Figure 8A shows eight trajectories with trajectories imposed for the four numbers 1, 2, 3, 8 and the four letters a, b, e, n. FIG. 8B shows corresponding plots reproduced experimentally according to what has been explained for FIGS. 2A, 3A and 4A, whereas FIGS. 8C and 8D correspond to the conditions exposed for FIGS. 2B, 3B, 4B and 2C respectively, 3C, 4C, that is to say for the ankle or wrist.

Claims

claims

1. Apparatus for sensing to a living being sensations of virtual movements of a part of its body (1), comprising a control unit (30, 40, 41, 42, 43) comprising in memory a table (30) ) containing a first plurality (Pl) of elementary excitation signals serving as constituent elements of a second plurality (P2) of macro-patterns (31, 32) each constituted by a third eigenvector (P3) of said elementary signals , the control unit (30, 40, 41, 42, 43) comprising a sequencer (43) arranged to read the macro-patterns (31, 32) and to output a said second plurality (P2) of corresponding excitation commands , in each case, a said third own plurality (P3) of vibrators (61) selected from a said first plurality (Pl) of vibrators (61) carried by a coupling support (3) in respective predetermined zones of the part of the body (1), the excitation of the said third plurality p a ropre (P3) of vibrators (61) by said second plurality (P2) of commands being provided for mechanically stimulating body elements of said body part of the living being to cause the creation of bioelectric signals in the living being him perceiving sensations of a given virtual movement of said part of his body.

2. Device for generating bioelectric signals, providing a living being sensations corresponding to the execution of a given movement of a part of his body (1) even if this movement is not executed, comprising: a table (30) elementary excitation signals,

a control unit (30, 40, 41, 42, 43) comprising a sequencer (43), vibrators (61) carried by a coupling support (3) holding each of them in a predetermined position with respect to bodily elements of the body part (1), in which, for each given movement, each vibrator can receive an elementary excitation signal so that it mechanically stimulates bodily elements of the body part to cause the emission of bioelectrical signals, the set of elementary excitation signals of the different vibrators constituting a macro-pattern, these elementary signals being chosen to constitute a macro- specific pattern characteristic of the movement considered, this macro-pattern read by the sequencer (43) giving the vibrators (61) elementary excitation signals capable of causing the creation of bioelectric signals in the living being making him perceive the sensations of execution of said movement.

3. Device according to claim 1 or 2, wherein the body elements stimulated by the vibrators (61) are tendons belonging to muscles that would be involved in the actual execution of the movement corresponding to the virtual movement whose sensations are to be caused.

4. Device according to any one of claims 1 to 3, which is provided for functional rehabilitation.

5. Device according to any one of claims 1 to 4, wherein the coupling support (3) is provided to limit voluntary movements of the body part (1) or to immobilize said part of the body.

6. Device according to claim 4 which is provided for assistance with the locomotion and rehabilitation of the latter.

7. Device according to any one of claims 1 to 3, which is provided for the learning or improvement of a gesture.

8. Device according to any one of claims 1 to 7, wherein each macro-pattern (31, 32) comprises data specifying a modulation of amplitude and / or frequency of the movement of the vibrator (61) over a period of predetermined excitation.

9. Device according to any one of claims 1 to 8, wherein the sequencer (43) is mechanically independent of the coupling medium (3), and connected to the vibrators (61) by a data link (49).

10. Device according to claim 9, wherein the link (49) is of the wireless type.

11. Device according to claim 10, wherein the vibrators (61) are controlled through a respective transponder (51).

12. Device according to claim 10, wherein the link (49) is provided by cellular telephone circuits or links with a data transmission network.

13. Virtual representation production system comprising a device according to any one of claims 1 to 3 which is functionally integrated therewith, for associating sensations of the sensory channels of the user sensations of perception of virtual movements.

14. System according to claim 13, characterized in that it constitutes a video game console in which the device according to any one of claims 1 to 3, which is functionally integrated therewith, is provided to cause a user to perceive movements that affect the representation on a screen that the video game attributes to that user.

15. A method for establishing the excitation macro-motifs (31, 32) of the device according to any one of claims 1 to 14, 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 (31) determined a priori, and, for a part of the body (1) considered, to make perceive to the subject person the sensations of a determined movement, the subject indicates the perception he has of the virtual movement thus evoked by the stimuli, and, by successive iterations, by changing parameters of the first macro-pattern (31, 32), determining final values of said parameters corresponding to a satisfactory emulation of the simulated real movement, and having repeated the cycle of previous steps a number of times to obtain the desired number of macro-patterns (31, 32), the parameters thereof are stored in said table (30).

16. A method according to claim 15, in which one determines which muscles exist in the part of the body considered which are involved in a real execution of the simulated movement, and the execution of the successive cycles is continued until a number has been developed. sufficient macro-patterns (31, 32) for each of said muscles to be processed by at least one of the macro-motifs (31, 32).

The method according to claim 15 or 16, wherein the stimuli are obtained from the macro-motifs (31, 32) resulting from the elementary signals picked up in the nerve, close to the sensory fibers from the physiological receptors, and recorded in the database (10).

18. A method for establishing the artificial macro-patterns (38, 39) for excitation of the device according to any one of claims 1 to 14, comprising the following steps: the instantaneous velocity vectors of course of a given trajectory are determined for points of this trajectory spaced apart in time, we identify the muscles that would be involved if a living being executed the movement corresponding to the said trajectory, we identify the directions of maximum sensitivity of these muscles, we establish the macromotifs by characterizing the constituent elementary signals of the macromotifs from an analysis of the velocity vectors with respect to the directions of maximum sensitivity.

19. The method of claim 18 wherein: the trajectory is recorded and smoothed using a low-pass filter, the determination of the velocity vectors is carried out for regularly spaced points in time, for example 200 ms.

20. The method of claim 18 or 19, wherein the respective frequency of the elementary signals is determined by setting it at a maximum excitation frequency of the corresponding vibrators, for example 100 Hz, when the velocity vectors are oriented in the direction of sensitivity. maximum of the corresponding muscle, and fixing it at an excitation frequency which is lower as the orientation of the velocity vectors moves away angularly from the maximum sensitivity direction of the muscle considered, until reaching a minimum value excitation of the corresponding vibrators, for example 1 Hz.

21. The method of claim 20 wherein the frequency of the elementary signals is determined with respect to the maximum vibration frequency of the vibrators as a function of the cosine of the angle between the velocity vectors and the direction of maximum sensitivity of the muscle considered.

22. The method according to claim 18, wherein the amplitude of the elementary signals is set at a predetermined value, for example 0.25 mm peak-to-peak.

23. The method according to claim 22, wherein the macromotifs are established by characterizing the frequency of the constituent elementary signals of the macromotifs from the analysis of the velocity vectors with respect to the directions of maximum sensitivity.

24. Method according to any one of claims 18 to 23 wherein: velocity vectors are determined in a reference system, for example in orthogonal coordinates, the maximum sensitivity directions of the muscles are represented in a reference system of the same type. .

25. The method of claim 24, wherein the determination of the velocity vectors and the representation of the directions of maximum sensitivity are performed in a single reference system.

26. A method according to any one of claims 18 to 25, wherein the artificial macro-patterns established (38, 39) relate to a movement relative to a trajectory whose execution involves a single articulation, for example the ankle or wrist. .

27. The method of claims 25 and 26 wherein the reference system common to the determination of velocity vectors and the representation of the directions of maximum sensitivity of the muscles is centered on the joint, and is a system of orthonormal axes.

28. The method according to claims 25 and 26 wherein the reference system common to the determination of the velocity vectors and the representation of the directions of maximum sensitivity of the muscles is centered on the end of a segment of the body part concerned by the movement corresponding to the trajectory.

The method of any one of claims 18 to 28, wherein the trajectory is two-dimensional.

30. A method according to any one of claims 18 to 28 wherein the trajectory is three-dimensional.