(19)
(11)EP 2 905 005 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
12.10.2016 Bulletin 2016/41

(21)Application number: 15153160.5

(22)Date of filing:  30.01.2015
(51)Int. Cl.: 
A61H 1/02  (2006.01)

(54)

Rehabilitation system

Rehabilitationssystem

Système de rééducation


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 06.02.2014 JP 2014021530

(43)Date of publication of application:
12.08.2015 Bulletin 2015/33

(73)Proprietor: Toyota Jidosha Kabushiki Kaisha
Toyota-shi, Aichi 471-8571 (JP)

(72)Inventors:
  • Shimoda, Shingo
    Wako-shi, Saitama 351-0198 (JP)
  • Sk Shibata ALNAJJAR, Fady
    Wako-shi, Saitama 351-0198 (JP)
  • Berenz, Vincent
    Wako-shi, Saitama 351-0198 (JP)
  • Yamada, Hitoshi
    Toyota-shi, Aichi 471-8571 (JP)
  • Yamashita, Masashi
    Toyota-shi, Aichi 471-8571 (JP)
  • Izuo, Takashi
    Toyota-shi, Aichi 471-8571 (JP)
  • Takagi, Soya
    Toyota-shi, Aichi 471-8571 (JP)

(74)Representative: TBK 
Bavariaring 4-6
80336 München
80336 München (DE)


(56)References cited: : 
EP-B1- 1 727 591
JP-A- 2003 339 908
JP-A- H08 229 015
US-B1- 8 165 685
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND OF THE INVENTION


    1. Field of the Invention



    [0001] The invention relates to a rehabilitation system that assists an action of a paretic arm due to brain damage, such as a stroke.

    2. Description of Related Art



    [0002] A stroke patient mostly has a paretic arm or leg on one side. To move the paretic arm or leg, a brain and muscles need to operate normally. A process of generating myoelectricity by one's own intention is important for such a hemiplegia patient in rehabilitation. A system described in Japanese Patent Application Publication No. 8-229015 (JP 8-229015 A) includes myoelectric potential detecting means for detecting a myoelectricity that is generated as a result of human's muscle activity. The system displays information, detected by the myoelectric potential detecting means, on a display unit. Thus, the system causes a patient to recognize that the body is moved by the action of the patient by oneself. A system described in Japanese Patent Application Publication No. 2003-339908 (JP 2003-339908 A) includes myoelectric potential sensors in correspondence with muscles and displays indicators corresponding to the myoelectric potential sensors as a human icon. Thus, it is possible to acquire the state of the muscle of each portion.

    [0003] Document US-B1-8165685 discloses a rehabilitation system suitable for assisting an action of a paretic arm due to brain damage, the rehabilitation system comprising: a detecting unit suitable to detect the position or muscle contraction in a healthy arm; an assist unit suitable for causing the paretic arm to carry out bending and stretching actions; an adjustment unit suitable for adjusting an operation timing, operation speed, bending load or stretching load of the assist unit in response to detection by the detecting unit; and a control unit configured to cause the assist unit to operate in accordance with the operation timing, operation speed, bending load or stretching load, adjusted by the adjustment unit.

    SUMMARY OF THE INVENTION



    [0004] An absolutely immovable paretic arm does not generate myoelectricity. Even when an absolutely immovable paretic arm is moved by external assistance, myoelectricity is not generated. However, the inventors found a matter that even a paretic arm that does not generate myoelectricity with external assistance generates myoelectricity if the paretic arm is supported by one's own healthy arm.

    [0005] The invention provides a rehabilitation system that is able to improve rehabilitation effect by particularly causing a paretic arm, which does not generate myoelectricity, to generate myoelectricity.

    [0006] An aspect of the invention relates to a rehabilitation system that assists an action of a paretic arm due to brain damage. The rehabilitation system includes: a detecting unit that detects an assist action that a healthy arm assists the paretic arm; an assist unit that causes the paretic arm to carry out bending and stretching actions; an adjustment unit that adjusts an operation timing, operation speed, bending load or stretching load of the assist unit in response to detection of the assist action by the detecting unit; and a control unit that causes the assist unit to operate in accordance with the operation timing, operation speed, bending load or stretching load, adjusted by the adjustment unit.

    [0007] In the above aspect, the detecting unit may detect support of a forearm of the paretic arm or a hand of the paretic arm by a hand of the healthy arm.

    [0008] In the above aspect, the detecting unit may include a first wearing device and a second wearing device, the first wearing device may be worn on the hand of the healthy arm, the second wearing device may be worn on the forearm of the paretic arm or the hand of the paretic arm, and the detecting unit may detect the assist action through contact of the first wearing device with the second wearing device or pressing of the first wearing device against the second wearing device.

    [0009] In the above aspect, the rehabilitation system may further include: a myoelectric sensor that detects a myoelectric potential of the paretic arm; and an output unit that informs that the myoelectric potential has been detected by the myoelectric sensor.

    [0010] In the above aspect, the assist unit may be a myoelectric stimulation device. The myoelectric stimulation device may stimulate the paretic arm in accordance with the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor.

    [0011] In the above aspect, the output unit may display a video image of movement of the paretic arm in response to detection of the myoelectric potential by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor.

    [0012] In the above aspect, the output unit may display, through a head-worn display, the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor and a video image of movement of the paretic arm in a superimposed manner.

    [0013] In the above aspect, the adjustment unit may adjust the operation timing, operation speed, bending load or stretching load of the assist unit in response to detection of the myoelectric potential by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor.

    [0014] In the above aspect, the adjustment unit may adjust the operation timing, operation speed, bending load or stretching load of the assist unit by comparing a target value generated by inputting a myoelectric potential or muscle synergy of the healthy arm or an arm of a healthy person as a model with the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor.

    [0015] According to the aspect of the invention, it is possible to improve rehabilitation effect by particularly causing a paretic arm, which does not generate myoelectricity, to generate myoelectricity.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0016] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

    FIG. 1 is a block diagram for implementing a rehabilitation system according to an embodiment of the invention;

    FIG. 2 is a block diagram for implementing a rehabilitation system according to another embodiment of the invention;

    FIG. 3 is a graph that shows a similarity L calculated for the number of synergies n for a behavior;

    FIG. 4A and FIG. 4B are characteristic graphs that respectively show experimental examples; and

    FIG. 5 is a characteristic graph that shows an experimental example.


    DETAILED DESCRIPTION OF EMBODIMENTS



    [0017] A first embodiment of the invention provides a rehabilitation system. The rehabilitation system includes a detecting unit, an assist unit, an adjustment unit and a control unit. The detecting unit detects an assist action that a healthy arm assists a paretic arm. The assist unit causes the paretic arm to carry out bending and stretching actions. The adjustment unit adjusts an operation timing, operation speed, bending load or stretching load of the assist unit in response to detection of the assist action by the detecting unit. The control unit causes the assist unit to operate in accordance with the operation timing, operation speed, bending load or stretching load, adjusted by the adjustment unit. According to the present embodiment, the operation timing, operation speed, bending load or stretching load is adjusted in response to the fact that the healthy arm assists the paretic arm as a trigger. Therefore, it is easy to generate myoelectricity caused by self-support, so it is possible to improve rehabilitation effect.

    [0018] A second embodiment of the invention provides a rehabilitation system in which, in the rehabilitation system according to the first embodiment, the detecting unit detects support of a forearm of the paretic arm or a hand of the paretic arm by a hand of the healthy arm. According to the present embodiment, by memorizing a state where a body image is easily recalled, the effect of self-support improves.

    [0019] A third embodiment of the invention provides a rehabilitation system in which, in the rehabilitation system according to the second embodiment, the detecting unit includes a first wearing device and a second wearing device. The first wearing device is worn on the hand of the healthy arm. The second wearing device is worn on the forearm of the paretic arm or the hand of the paretic arm. The detecting unit detects the assist action through contact of the first wearing device with the second wearing device or pressing of the first wearing device against the second wearing device. According to the present embodiment, it is possible to achieve reliable self-support.

    [0020] A fourth aspect of the invention provides a rehabilitation system in which the rehabilitation system according to any one of the first to third embodiments further includes a myoelectric sensor and an output unit. The myoelectric sensor detects a myoelectric potential of .the paretic arm. The output unit informs that the myoelectric potential has been detected by the myoelectric sensor. According to the present embodiment, it is possible to facilitate rehabilitation by informing detection of the myoelectric potential of the paretic arm.

    [0021] A fifth embodiment of the invention provides a rehabilitation system in which, in the rehabilitation system according to the fourth embodiment, the assist unit is a myoelectric stimulation device. The myoelectric stimulation device stimulates the paretic arm in accordance with the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated on the basis of the myoelectric potential detected by myoelectric sensor. According to the present embodiment, it is possible to improve the control accuracy and response speed of the assist unit as compared to a mechanical assist unit.

    [0022] A sixth embodiment of the invention provides a rehabilitation system in which, in the rehabilitation system according to the fourth or fifth embodiment, the output unit displays a video image of movement of the paretic arm in response to detection of the myoelectric potential by the myoelectric sensor or a muscle synergy calculated on the basis of the myoelectric potential detected by the myoelectric sensor. According to the present embodiment, it is possible to further facilitate rehabilitation owing to visual effect.

    [0023] A seventh embodiment of the invention provides a rehabilitation system in which, in the rehabilitation system according to the fourth or fifth embodiment, the output unit displays, through a head-worn display, the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated on the basis of the myoelectric potential detected by the myoelectric sensor and a video image of movement of the paretic arm in a superimposed manner. According to the present embodiment, a patient is allowed to deeply concentrate into augmented reality, so it is possible to further facilitate rehabilitation owing to visual effect.

    [0024] An eighth embodiment of the invention provides a rehabilitation system in which, in the rehabilitation system according to any one of the fourth to seventh embodiments, the adjustment unit adjusts the operation timing, operation speed, bending load or stretching load of the assist unit in response to detection of the myoelectric potential by the myoelectric sensor or a muscle synergy calculated on the basis of the myoelectric potential detected by the myoelectric sensor. According to the present embodiment, by adjusting the operation timing, operation speed, bending load or stretching load of the assist unit in response to detection of an actual myoelectric potential of the paretic arm, myoelectricity is easily generated, so it is possible to improve rehabilitation effect.

    [0025] A ninth embodiment of the invention provides a rehabilitation system in which, in the rehabilitation system according to any one of the fourth to seventh embodiments, the adjustment unit adjusts the operation timing, operation speed, bending load or stretching load of the assist unit by comparing a target value generated by inputting a myoelectric potential or muscle synergy of the healthy arm or an arm of a healthy person as a model with the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated on the basis of the myoelectric potential detected by the myoelectric sensor. According to the present embodiment, it is possible to carry out assistance according to the degree of recovery.

    Embodiment



    [0026] FIG. 1 is a block diagram for implementing a rehabilitation system according to an embodiment of the invention. The rehabilitation system according to the embodiment of the invention is a rehabilitation system that assists an action of a paretic arm due to brain damage, such as a stroke. The rehabilitation system includes a detecting unit 10, an assist unit 20, an adjustment unit 30 and a control unit 40. The detecting unit 10 detects an assist action that a healthy arm assists the paretic arm. The assist unit 20 causes the paretic arm to carry out bending and stretching actions. The adjustment unit 30 adjusts an operation timing, operation speed, bending load or stretching load of the assist unit 20 in response to detection of the assist action by the detecting unit 10. The control unit 40 causes the assist unit 20 to operate in accordance with the operation timing, operation speed, bending load or stretching load, adjusted by the adjustment unit 30.

    [0027] The detecting unit 10 detects support of a forearm of the paretic arm or a hand of the paretic arm by a hand of the healthy arm, that is, an assisting action (assist action). As shown in FIG. 1, the detecting unit 10 includes a first wearing device 11 and a second wearing device 12. The first wearing device 11 is worn on the hand of the healthy arm. The second wearing device 12 is worn on the forearm of the paretic arm or the hand of the paretic arm. The detecting unit 10 detects the assist action through contact of the first wearing device 11 with the second wearing device 12 or pressing of the first wearing device 11 against the second wearing device 12. For example, it is applicable that the first wearing device 11 is formed of a glove including a first electrode, the second wearing device 12 is formed of a glove including a second electrode, and the detecting unit 10 detects contact of the first electrode with the second electrode as movement of the healthy arm for assisting the paretic arm. Alternatively, it is applicable that the first wearing device 11 is formed of a glove including a first pressing switch, the second wearing device 12 is formed of a glove including a second pressing switch, and the detecting unit 10 detects pressing of the first pressing switch against the second pressing switch as movement of the healthy arm for assisting the paretic arm. The detecting unit 10 not only detects a change between an on state and an off state resulting from contact or pressing as the assist action but also may detect a pressing value. The detecting unit 10 may be formed of a motion capture. The assist unit 20 is an actuator that bends or stretches the forearm with respect to an upper arm.

    [0028] The adjustment unit 30 starts the operation of the assist unit 20 when the detecting unit 10 detects the assist action of the healthy arm. By starting the operation of the assist unit 20, support by the healthy arm is assisted, and it is possible to make a patient to recall the body image. The adjustment unit 30 increases the operation speed of the assist unit 20 when the detecting unit 10 detects the assist action of the healthy arm. By increasing the operation speed of the assist unit 20, support by the healthy arm is assisted, and it is possible to make a patient to recall the body image. Conversely, the adjustment unit 30 may reduce the operation speed of the assist unit 20 when the detecting unit 10 detects the assist action of the healthy arm. By reducing the operation speed of the assist unit 20, support force by the healthy arm is increased, and it is possible to cause a patient to recall the body image. The adjustment unit 30 reduces the bending load or stretching load of the assist unit 20 when the detecting unit 10 detects the assist action of the healthy arm. By reducing the bending load or stretching load of the assist unit 20, support by the healthy arm is assisted, and it is possible to cause a patient to recall the body image. Conversely, the adjustment unit 30 may increase the bending load or stretching load of the assist unit 20 when the detecting unit 10 detects the assist action of the healthy arm. By increasing the bending load or stretching load of the assist unit 20, support force by the healthy arm is increased, and it is possible to cause a patient to recall the body image. In this way, the adjustment unit 30 adjusts at least any one of the operation timing, operation speed, bending load or stretching load of the assist unit 20, and may adjust any two or more of the operation timing, operation speed, bending load and stretching load of the assist unit 20 in combination.

    [0029] When the detecting unit 10 detects the pressing value, it is possible to change the operation timing, operation speed, bending load or stretching load of the assist unit 20 in accordance with the magnitude of the pressing value. In this way, the rehabilitation system according to the present embodiment adjusts the operation timing, operation speed, bending load or stretching load in response to the fact that the healthy arm assists the paretic arm as a trigger. Thus, it is easy to generate myoelectricity caused by self-support, so it is possible to improve rehabilitation effect.

    [0030] The rehabilitation system according to the present embodiment further includes a myoelectric sensor 50 and an output unit 60. The myoelectric sensor 50 detects the myoelectric potential of a biceps muscle of arm, triceps muscle of arm, or the like, of the paretic arm. The output unit 60 informs that the myoelectric potential has been detected by the myoelectric sensor 50. By informing detection of the myoelectric potential of the paretic arm, it is possible to facilitate rehabilitation. For example, the following sensor may be used as the myoelectric sensor 50. A plurality of electrodes are mounted on a muscle to be measured, a reference electrode band and a power supply are connected to the plurality of electrodes, and the waveform of the amount of activity of the muscle is measured. For example, display means is used as the output unit 60. The output unit 60 displays a video image of movement of the paretic arm in response to detection of the myoelectric potential by the myoelectric sensor 50. By displaying the video image of movement of the paretic arm with the display means, it is possible to further facilitate rehabilitation owing to visual effect. The video image of movement of the paretic arm may be created by capturing the action of the healthy arm and then inverting the action data of the healthy arm or may be created by computer graphic. Alternatively, on the display means, the size of a display object may be changed in accordance with the magnitude of a myoelectricity value. The output unit 60 may output sound in addition to a display. The adjustment unit 30 is able to adjust the operation timing, operation speed, bending load or stretching load of the assist unit 20 in response to detection of the myoelectric potential by the myoelectric sensor 50. By adjusting the operation timing, operation speed, bending load or stretching load of the assist unit 20 in response to detection of an actual myoelectric potential of the paretic arm, it is easy to generate myoelectricity, and it is possible to improve rehabilitation effect.

    [0031] The adjustment unit 30 starts the operation of the assist unit 20 when the myoelectric sensor 50 detects the myoelectric potential. By starting the operation of the assist unit 20, it is possible to recognize generation of an actual myoelectric potential, so it is possible to improve rehabilitation effect. The adjustment unit 30 increases the operation speed of the assist unit 20 when the myoelectric sensor 50 detects the myoelectric potential. By increasing the operation speed of the assist unit 20, it is possible to recognize generation of an actual myoelectric potential, so it is possible to improve rehabilitation effect. Conversely, the adjustment unit 30 may reduce the operation speed of the assist unit 20 when the myoelectric sensor 50 detects the myoelectric potential. By reducing the operation speed of the assist unit 20, it is possible to recognize generation of an actual myoelectric potential, so it is possible to improve rehabilitation effect. The adjustment unit 30 reduces the bending load or stretching load of the assist unit 20 when the myoelectric sensor 50 detects the myoelectric potential. By reducing the bending load or stretching load of the assist unit 20, it is possible to recognize generation of an actual myoelectric potential, so it is possible to improve rehabilitation effect. Conversely, the adjustment unit 30 may increase the bending load or stretching load of the assist unit 20 when the myoelectric sensor 50 detects the myoelectric potential. By increasing the bending load or stretching load of the assist unit 20, it is possible to recognize generation of an actual myoelectric potential, so it is possible to improve rehabilitation effect.

    [0032] Adjustment by the adjustment unit 30, which is carried out in response to detection of the myoelectric potential by the myoelectric sensor 50, is carried out together with adjustment of the assist action that is detected by the detecting unit 10. The adjustment unit 30 is able to start the operation of the assist unit 20 in response to both detection of the assist action by the detecting unit 10 and detection of the myoelectric potential by the myoelectric sensor 50. Alternatively, the adjustment unit 30 may start the operation of the assist unit 20 in response to one of detection of the assist action by the detecting unit 10 and detection of the myoelectric potential by the myoelectric sensor 50. Alternatively, the adjustment unit 30 may start the operation of the assist unit 20 in response to detection of the assist action by the detecting unit 10, and may adjust the operation speed, bending load or stretching load of the assist unit 20 in response to detection of the myoelectric potential by the myoelectric sensor 50. Alternatively, the adjustment unit 30 may increase the operation speed of the assist unit 20 or reduce the operation speed of the assist unit 20 in response to both detection of the assist action by the detecting unit 10 and detection of the myoelectric potential by the myoelectric sensor 50. Alternatively, the adjustment unit 30 may increase the operation speed of the assist unit 20 or reduce the operation speed of the assist unit 20 in response to one of detection of the assist action by the detecting unit 10 and detection of the myoelectric potential by the myoelectric sensor 50. Alternatively, the adjustment unit 30 may increase the operation speed of the assist unit 20 or reduce the operation speed of the assist unit 20 in response to detection of the assist action by the detecting unit 10, and may adjust the bending load or stretching load in response to detection of the myoelectric potential by the myoelectric sensor 50. The adjustment unit 30 reduces the bending load or stretching load of the assist unit 20 or increases the bending load or stretching load of the assist unit 20 in response to both detection of the assist action by the detecting unit 10 and detection of the myoelectric potential by the myoelectric sensor 50. Alternatively, the adjustment unit 30 may reduce the bending load or stretching load of the assist unit 20 or increase the bending load or stretching load of the assist unit 20 in response to one of detection of the assist action by the detecting unit 10 and detection of the myoelectric potential by the myoelectric sensor 50. Alternatively, the adjustment unit 30 may reduce the bending load or stretching load of the assist unit 20 or increase the bending load or stretching load of the assist unit 20 in response to detection of the assist action by the detecting unit 10, and may adjust the operation speed of the assist unit 20 in response to detection of the myoelectric potential by the myoelectric sensor 50.

    [0033] Adjustment by the adjustment unit 30, which is carried out in response to detection of the myoelectric potential by the myoelectric sensor 50, may be carried out instead of adjustment of the assist action that is detected by the detecting unit 10. The adjustment unit 30 may adjust the operation timing, operation speed, bending load or stretching load of the assist unit 20 by comparing a target value generated by inputting the myoelectric potential of the healthy arm as a model with the myoelectric potential detected by the myoelectric sensor 50. As a result, it is possible to perform assistance with the use of the assist unit 20 according to the degree of recovery. The target value may be generated by inputting the myoelectric potential of a healthy person in an ideal state as a model, instead of the myoelectric potential of the healthy arm.

    [0034] FIG. 2 is a block diagram for implementing a rehabilitation system according to another embodiment of the invention. Only the components different from those of the above-described embodiment will be described. Like reference numerals denote the same functional units, and the description thereof is omitted. In the present embodiment, the assist unit 20 uses a myoelectric stimulation device instead of the actuator. The rehabilitation system further includes a muscle synergy calculation unit 80. The muscle synergy calculation unit 80 calculates a muscle synergy on the basis of the myoelectric potential detected by the myoelectric sensor 50. The myoelectric stimulation device applies electrical stimulation in accordance with the calculated result of the muscle synergy calculation unit 80, and causes the forearm to bend or stretch with respect to the upper arm. The muscle synergy is a form of expression of a phenomenon that, when a human performs a behavior or performs a task consisting of one or more behaviors, a plurality of muscles cooperatively work with redundancy. In the present embodiment, the adjustment unit 30 is able to adjust the operation timing, operation speed, bending load or stretching load of the assist unit 20 in response to the muscle synergy calculated on the basis of the myoelectric potential detected by the myoelectric sensor 50. The adjustment unit 30 adjusts the operation timing, operation speed, bending load or stretching load of the assist unit 20 by comparing a target value generated by inputting a muscle synergy of the healthy arm as a model with a muscle synergy calculated on the basis of the myoelectric potential detected by the myoelectric sensor 50. Thus, it is possible to perform assistance according to the degree of recovery with the use of the assist unit 20. The target value may be generated by inputting a muscle synergy of a healthy person in an ideal state as a model, instead of the muscle synergy of the healthy arm. In the present embodiment, the output unit 60 displays, through a head-worn display, the myoelectric potential detected by the myoelectric sensor 50 or the muscle synergy based on the myoelectric potential detected by the myoelectric sensor 50 and a video image of movement of the paretic arm in a superimposed manner. For example, a head mount display may be used as the head-worn display. The head-worn display includes an angle sensor 70. The angle sensor 70 detects the angle of a head. The output unit 60 displays a video image (augmented reality) according to the head angle detected by the angle sensor 70 on the head-worn display. In this way, a patient wears the head-worn display, and an arm created by computer graphic in accordance with the myoelectric potential or the muscle synergy and the actual arm of the patient are displayed in a superimposed manner. Thus, the patient is allowed to concentrate into augmented reality, so rehabilitation effect improves. The magnitude of the muscle synergy may be converted to the color image of a skin and then projected onto the arm of the patient. When augmented reality is displayed, the assist unit 20 is not displayed and a video image is displayed as if only the arm of the patient is moving by itself. Thus, the patient is allowed to concentrate into augmented reality, so rehabilitation effect further improves.

    [0035] Calculation of the muscle synergy will be described in more detail. Initially, the myoelectric sensor 50 acquires time-series myoelectric potentials of each of muscles 1, 2, ..., m while a patient is performing a behavior. In the present embodiment, myoelectric potentials at m points of a body of the patient are measured. Points at which a myoelectric potential should be measured are muscles associated with the behavior (for example, bending and stretching of right hand) of a portion (for example, right hand) for training.

    [0036] Measurement is performed from the start of a behavior to the end of the behavior at constant time intervals. A value of myoelectric potential of the i-th muscle at the j-th timing is stored in the i-th row and j-th column element M[i,j] of a myoelectric potential matrix M. That is, the myoelectric potential matrix M is configured such that a row vector M(1) consisting of time-series myoelectric potentials of the muscle 1, a row vector M(2) consisting of time-series myoelectric potentials of the muscle 2, ..., and a row vector M(m) consisting of time-series myoelectric potentials of the muscle m are arranged in rows.

    [0037] Thus, the number of rows of the myoelectric potential matrix M is m. The number of columns of the myoelectric potential matrix M changes with the time length of measurement, that is, the time length of a behavior, and the frequency or interval of measurement during the behavior.

    [0038] In this way, when the myoelectric potential matrix M is acquired, the muscle synergy calculation unit 80 calculates a muscle synergy matrix W, a control matrix C and an error matrix E so that M = WC + E. At this time, non-negative matrix factorization is used.

    [0039] Hereinafter, for the sake of easy understanding, description will be made by omitting a suffix k where appropriate.

    [0040] In non-negative matrix factorization, the degree of error is minimized or a similarity L is maximized.

    [0041] Where the number of columns of the myoelectric potential matrix M, the number of columns of the control matrix C and the number of columns of the error matrix E all are t, the number of rows of the myoelectric potential matrix M, the number of rows of the muscle synergy matrix W and the number of rows of the error matrix E all are m, and the number of columns of the muscle synergy matrix W and the number of rows of the control matrix C all are n, the similarity L may be defined as follows.



    [0042] Here, n is a numeric value that indicates the number of synergies. Generally, when n is increased, L also increases. An appropriate value of n may also be determined as follows by using non-negative matrix factorization as needed.

    [0043] Generally, in non-negative matrix factorization, it is desired to select the number of synergies n so that the similarity L is higher than or equal to 70%. On the other hand, when the number of synergies n is too large, not only a calculation load increases but also over-adaptation occurs, with the result that an appropriate process is not executed on the contrary.

    [0044] Therefore, the following method is used.

    [0045] That is, for each of n = 1, 2, 3, 4, ..., the above-described similarity L is calculated.

    [0046] FIG. 3 is a graph that shows the similarity L calculated for the number of synergies n for a behavior. Hereinafter, description will be made with reference to FIG. 3.

    [0047] In FIG. 3, the abscissa axis Number of synergies n represents the number of synergies n, and the ordinate axis Similarity L (%) represents the similarity L. As shown in FIG. 3, it appears that, as the number of synergies n increases, the similarity L also increases; however, the degree of increase in similarity L is saturated at the number of synergies n of about 5, and the similarity L is higher than or equal to 70%. Thus, a numeric value before or after the beginning of saturation, for example, 4, 5 or 6, may be employed as the number of synergies n for the following calculation.

    [0048] The number of synergies n may be a value different for each individual patient. Alternatively, the number of synergies n may be a value common to all the patients because it is presumable that there is no large difference in the number of synergies when a human performs a behavior. In the latter case, some patients are caused to perform a behavior experimentally in advance, an adequate value of n is determined by non-negative matrix factorization, and, thereafter, the determined value of n is directly used for the other patients as well.

    [0049] In this model, it is assumed that, when the central nerve of a patient supplies n control signals C(1), C(2), ..., C(n) to m muscles, the muscle 1 attempts to move so that the myoelectric potential WC(1) is satisfied, the muscle 2 attempts to move so that the myoelectric potential WC(2) is satisfied, ..., and the muscle m attempts to move so that the myoelectric potential WC(m) is satisfied.

    [0050] FIG. 4A to FIG. 5 are characteristic graphs that respectively show experimental examples. In these experiments, a hemiplegia patient of which a right arm is an absolutely immovable paretic arm is employed as a subject. FIG. 4A is a characteristic graph of the myoelectric potential at the time when the paretic arm is moved with external assistance. FIG. 4B is a characteristic graph of the myoelectric potential at the time when the paretic arm is moved by self-support, that is, the healthy arm. It appears that no myoelectricity is generated in FIG. 4A and myoelectricity is apparently generated in FIG. 4B.

    [0051] FIG. 5 is a characteristic graph of the myoelectric potential of the same subject who has undergone rehabilitation through self-support for about two months. In FIG. 5, a time during which the paretic arm is intended to be moved without support is denoted by T1, a time during which the paretic arm is moved with external assistance is denoted by T2, and a time during which the paretic arm is moved with the healthy arm through self-support is denoted by T3. No myoelectricity is generated during the time T1; whereas myoelectricity is generated during the time T2. In this way, when the patient undergoes rehabilitation through self-support, myoelectricity is generated even with external assistance. When the paretic arm is moved with the healthy arm through self-support as shown during the time T3, it appears that a larger myoelectricity than that in the case of external assistance is generated.

    [0052] According to the invention, it is possible to generate myoelectricity in the absolutely immovable paretic arm.

    [0053] A rehabilitation system that assists an action of a paretic arm due to brain damage, such as a stroke, includes: a detecting unit (10) that detects an assist action that a healthy arm assists the paretic arm; an assist unit (20) that causes the paretic arm to carry out bending and stretching actions; an adjustment unit (30) that adjusts an operation timing, operation speed, bending load or stretching load of the assist unit (20) in response to detection of the assist action by the detecting unit (10); and a control unit (40) that causes the assist unit (20) to operate in accordance with the operation timing, operation speed, bending load or stretching load, adjusted by the adjustment unit (30).


    Claims

    1. A rehabilitation system suitable for assisting an action of a paretic arm due to brain damage, the rehabilitation system comprising:

    a detecting unit (10) suitable for detecting an assist action that a healthy arm of a patient assists the paretic arm of the patient ;

    an assist unit (20) suitable for causing the paretic arm to carry out bending and stretching actions;

    an adjustment unit (30) suitable for adjusting an operation timing, operation speed, bending load or stretching load of the assist unit in response to detection of the assist action by the detecting unit; and

    a control unit (40) configured to cause the assist unit to operate in accordance with the operation timing, operation speed, bending load or stretching load, adjusted by the adjustment unit.


     
    2. The rehabilitation system according to claim 1, characterized in that
    the detecting unit is suitable for detecting support of a forearm of the paretic arm or a hand of the paretic arm by a hand of the healthy arm.
     
    3. The rehabilitation system according to claim 2, characterized in that
    the detecting unit includes a first wearing device and a second wearing device, the first wearing device is suitable for being worn on the hand of the healthy arm, the second wearing device is suitable for being worn worn on the forearm of the paretic arm or the hand of the paretic arm, and the detecting unit is suitable for detecting the assist action through contact of the first wearing device with the second wearing device or pressing of the first wearing device against the second wearing device.
     
    4. The rehabilitation system according to any one of claims 1 to 3, characterized by further comprising:

    a myoelectric sensor (50) suitable for detecting a myoelectric potential of the paretic arm; and

    an output unit (60) suitable for informing that the myoelectric potential has been detected by the myoelectric sensor.


     
    5. The rehabilitation system according to claim 4, characterized in that
    the assist unit is a myoelectric stimulation device, and
    the myoelectric stimulation device is suitable for stimulating the paretic arm in accordance with the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor.
     
    6. The rehabilitation system according to claim 4 or 5, characterized in that
    the output unit is suitable for displaying a video image of movement of the paretic arm in response to detection of the myoelectric potential by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor.
     
    7. The rehabilitation system according to claim 4 or 5, characterized in that
    the output unit is suitable for displaying, through a head-worn display, the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor and a video image of movement of the paretic arm in a superimposed manner.
     
    8. The rehabilitation system according to any one of claims 4 to 7, characterized in that
    the adjustment unit is suitable for adjusting the operation timing, operation speed, bending load or stretching load of the assist unit in response to detection of the myoelectric potential by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor.
     
    9. The rehabilitation system according to any one of claims 4 to 7, characterized in that
    the adjustment unit is suitable for adjusting the operation timing, operation speed, bending load or stretching load of the assist unit by comparing a target value generated by inputting a myoelectric potential or muscle synergy of the healthy arm or an arm of a healthy person as a model with the myoelectric potential detected by the myoelectric sensor or a muscle synergy calculated based on the myoelectric potential detected by the myoelectric sensor.
     


    Ansprüche

    1. Rehabilitationssystem, das zu einer Unterstützung einer Aktion eines aufgrund eines Hirnschadens gelähmten Arms geeignet ist, wobei das Rehabilitationssystem umfasst
    eine Erfassungseinheit (10), die dazu geeignet ist, eine Unterstützungsaktion, dass ein gesunder Arm eines Patienten den gelähmten Arm des Patienten unterstützt, zu erfassen,
    eine Unterstützungseinheit (20), die dazu geeignet ist, den gelähmten Arm dazu zu bringen, Beuge- und Streckaktionen durchzuführen,
    eine Anpassungseinheit (30), die dazu geeignet ist, eine Betriebszeitsteuerung, eine Betriebsgeschwindigkeit, eine Beugelast oder eine Strecklast der Unterstützungseinheit als Reaktion auf eine Erfassung der Unterstützungsaktion mittels der Erfassungseinheit anzupassen, und
    eine Steuereinheit (40), die dazu eingerichtet ist, um die Unterstützungseinheit dazu zu bringen, gemäß der durch die Anpassungseinheit angepassten Betriebszeitsteuerung, Betriebsgeschwindigkeit, Beugelast oder Strecklast zu wirken.
     
    2. Rehabilitationssystem nach Anspruch 1, dadurch gekennzeichnet, dass
    die Erfassungseinheit dazu geeignet ist, eine Unterstützung eines Unterarms des gelähmten Arms oder einer Hand des gelähmten Arms mittels einer Hand des gesunden Arms zu erfassen.
     
    3. Rehabilitationssystem nach Anspruch 2, dadurch gekennzeichnet, dass
    die Erfassungseinheit eine erste Tragvorrichtung und eine zweite Tragvorrichtung umfasst, wobei die erste Tragvorrichtung dazu geeignet ist, an der Hand des gesunden Arms getragen zu werden, die zweite Tragvorrichtung dazu geeignet ist, an dem Unterarm des gelähmten Arms oder der Hand des gelähmten Arms getragen zu werden, und die Erfassungseinheit dazu geeignet ist, die Unterstützungsaktion mittels Kontakt der ersten Tragvorrichtung mit der zweiten Tragvorrichtung oder Drücken der ersten Tragvorrichtung gegen die zweite Tragvorrichtung zu erfassen.
     
    4. Rehabilitationssystem nach einem der Ansprüche 1 bis 3, ferner gekennzeichnet durch
    einen myoelektrischen Sensor (50), der dazu geeignet ist, ein myoelektrisches Potential des gelähmten Arms zu erfassen, und
    eine Ausgabeeinheit (60), die dazu geeignet ist, darüber zu informieren, dass das myoelektrische Potential mittels des myoelektrischen Sensors erfasst ist.
     
    5. Rehabilitationssystem nach Anspruch 4, dadurch gekennzeichnet, dass
    die Unterstützungseinheit eine myoelektrische Stimulationsvorrichtung ist, und
    die myoelektrische Stimulationsvorrichtung dazu geeignet ist, den gelähmten Arm gemäß dem mittels des myoelektrischen Sensors erfassten myoelektrischen Potentials oder einer basierend auf dem mittels des myoelektrischen Sensors erfassten myoelektrischen Potentials berechneten Muskelsynergie zu stimulieren.
     
    6. Rehabilitationssystem nach Anspruch 4 oder 5, dadurch gekennzeichnet, dass
    die Ausgabeeinheit dazu geeignet ist, ein Videobild einer Bewegung des gelähmten Arms als Reaktion auf eine Erfassung des myoelektrischen Potentials mittels des myoelektrischen Sensors oder eine basierend auf dem mittels des myoelektrischen Sensors erfassten myoelektrischen Potentials berechneten Muskelsynergie anzuzeigen.
     
    7. Rehabilitationssystem nach Anspruch 4 oder 5, dadurch gekennzeichnet, dass
    die Ausgabeeinheit dazu geeignet ist, das mittels des myoelektrischen Sensors erfasste myoelektrische Potential oder eine basierend auf dem mittels des myoelektrischen Sensors erfassten myoelektrischen Potentials berechneten Muskelsynergie und ein Videobild einer Bewegung des gelähmten Arms auf eine überlagerte Weise mittels einer kopfgetragenen Anzeige anzuzeigen.
     
    8. Rehabilitationssystem nach einem der Ansprüche 4 bis 7, dadurch gekennzeichnet, dass
    die Anpassungseinheit dazu geeignet ist, die Betriebszeitsteuerung, Betriebsgeschwindigkeit, Beugelast oder Strecklast der Unterstützungseinheit als Reaktion auf eine Erfassung des myoelektrischen Potentials mittels des myoelektrischen Sensors oder eine basierend auf dem mittels des myoelektrischen Sensors erfassten myoelektrischen Potentials berechneten Muskelsynergie anzupassen.
     
    9. Rehabilitationssystem nach einem der Ansprüche 4 bis 7, dadurch gekennzeichnet, dass
    die Anpassungseinheit dazu geeignet ist, die Betriebszeitsteuerung, Betriebsgeschwindigkeit, Beugelast oder Strecklast der Unterstützungseinheit durch Vergleich eines durch Eingabe eines myoelektrischen Potentials oder einer Muskelsynergie des gesunden Arms oder eines Arms einer gesunden Person als ein Modell erzeugten Zielwerts mit dem mittels des myoelektrischen Sensors erfassten myoelektrischen Potentials oder einer basierend auf dem mittels des myoelektrischen Sensors erfassten myoelektrischen Potentials berechneten Muskelsynergie anzupassen.
     


    Revendications

    1. Système de rééducation adapté pour assister une action d'un bras devenu parétique suite à un accident cérébral,
    le système de rééducation comprenant :

    une unité de détection (10) adaptée pour détecter une action d'assistance par laquelle un bras sain d'un patient assiste le bras parétique du patient ;

    une unité d'assistance (20) adaptée pour permettre au bras parétique de réaliser des actions de flexion et d'extension ;

    une unité d'ajustage (30) adaptée pour ajuster le chronométrage d'une opération, la vitesse d'une opération, la charge de flexion ou la charge d'extension de l'unité d'assistance en réponse à la détection de l'action d'assistance par l'unité de détection ; et

    une unité de contrôle (40) configurée pour permettre à l'unité d'assistance d'opérer conformément au chronométrage d'une opération, à la vitesse d'une opération, à la charge de flexion ou à la charge d'extension ajustés par l'unité d'ajustage.


     
    2. Système de rééducation selon la revendication 1, caractérisé en ce que
    l'unité de détection est adaptée pour détecter l'aide d'un avant-bras du bras parétique ou d'une main du bras parétique par une main du bras sain.
     
    3. Système de rééducation selon la revendication 2, caractérisé en ce que
    l'unité de détection contient un premier dispositif de port et un second dispositif de port, le premier dispositif de port étant adapté pour être porté sur la main du bras sain, le second dispositif de port étant adapté pour être porté sur l'avant-bras du bras parétique ou la main du bras parétique et l'unité de détection étant adaptée pour détecter l'action d'assistance via le contact du premier dispositif de port avec le second dispositif de port ou via la pression du premier dispositif de port contre le second dispositif de port.
     
    4. Système de rééducation selon l'une quelconque des revendications 1 à 3, caractérisé en ce qu'il comprend en outré :

    un capteur myoélectrique (50) adapté pour détecter un potentiel myoélectrique du bras parétique ; et

    une unité de sortie (60) adaptée pour informer que le potentiel myoélectrique a été détecté par le capteur myoélectrique.


     
    5. Système de rééducation selon la revendication 4, caractérisé en ce que
    l'unité d'assistance est un dispositif de stimulation myoélectrique, et
    le dispositif de stimulation myoélectrique est adapté pour stimuler le bras parétique conformément au potentiel myoélectrique détecté par le capteur myoélectrique ou à une synergie musculaire calculée en fonction du potentiel myoélectrique détecté par le capteur myoélectrique.
     
    6. Système de rééducation selon la revendication 4 ou 5, caractérisé en ce que
    l'unité de sortie est adaptée pour afficher une image vidéo du mouvement du bras parétique en réponse à la détection du potentiel myoélectrique par le capteur myoélectrique ou à une synergie musculaire calculée en fonction du potentiel myoélectrique détecté par le capteur myoélectrique.
     
    7. Système de rééducation selon la revendication 4 ou 5, caractérisé en ce que
    l'unité de sortie est adaptée pour afficher, via un écran porté sur la tête, le potentiel myoélectrique détecté par le capteur myoélectrique ou une synergie musculaire calculée en fonction du potentiel myoélectrique détecté par le capteur myoélectrique et une image vidéo du mouvement du bras parétique en superposition.
     
    8. Système de rééducation selon l'une quelconque des revendications 4 à 7, caractérisé en ce que
    l'unité d'ajustage est adaptée pour ajuster le chronométrage d'une opération, la vitesse d'une opération, la charge de flexion ou la charge d'extension de l'unité d'assistance en réponse à la détection du potentiel myoélectrique par le capteur myoélectrique ou à une synergie musculaire calculée en fonction du potentiel myoélectrique détecté par le capteur myoélectrique.
     
    9. Système de rééducation selon l'une quelconque des revendications 4 à 7, caractérisé en ce que
    l'unité d'ajustage est adaptée pour ajuster le chronométrage d'une opération, la vitesse d'une opération, la charge de flexion ou la charge d'extension de l'unité d'assistance en comparant une valeur cible générée en saisissant un potentiel myoélectrique ou une synergie musculaire du bras sain ou d'un bras d'une personne en pleine santé comme modèle, avec le potentiel myoélectrique détecté par le capteur myoélectrique ou une synergie musculaire calculée en fonction du potentiel myoélectrique détecté par le capteur myoélectrique.
     




    Drawing


















    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description