Patent Publication Number: US-2015081036-A1

Title: Movement assist device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2013-191381 filed with the Japan Patent Office on Sep. 17, 2013, the entire content of which is hereby incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     Disclosed embodiments relate to a movement assist device. 
     2. Related Art 
     Japanese Patent Application Laid-open Publication No. S61-228854 discloses dynamic force equipment such as an artificial leg. In this dynamic force equipment, the length of the connection member that connects two hydraulic actuators provided as joints is adjustable. Furthermore, inside the connection member, an oil passage for actuating the hydraulic actuator is provided. 
     SUMMARY 
     A movement assist device includes: a motor including a stator and a rotator; two arm members connected to each of the stator and the rotator and configured to be connected to a predetermined part of a body of an equipped person; a signal acceptor configured to accept a trigger signal that triggers a driving of the motor; and a driving controller configured to drive the motor so that the two arm members expand in response to a trigger that the signal acceptor accepts a first one of the trigger signal. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  and  FIG. 1B  are perspective views illustrating examples of movement assist devices of one embodiment that is attached to a person wearing hip joint equipment; 
         FIG. 2  is a perspective view illustrating an example of a motor and two arm members of the movement assist device; 
         FIG. 3  is a perspective view illustrating an example of an attachment structure of the motor and two arm members to the hip joint equipment; 
         FIG. 4A  and  FIG. 4B  are sectional views illustrating an example of sectional structures of connection parts of the two arm members and the hip joint equipment, respectively; 
         FIG. 5  is a schematic view illustrating an example of a manual switch of the movement assist device; 
         FIG. 6  is a schematic view illustrating an example of a sensor unit of the movement assist device; 
         FIG. 7  is a functional block diagram illustrating an example of a functional configuration of the movement assist device; 
         FIG. 8  is a schematic view illustrating an example of the sensor unit of the movement assist device when pressure-sensitive sensors are mounted on both legs; 
         FIG. 9  is a functional block diagram illustrating an example of the functional configuration of the movement assist device when the pressure-sensitive sensors are mounted on both legs; 
         FIG. 10  is a perspective view illustrating an example of the movement assist device when applied to knee joint equipment; 
         FIG. 11  is a perspective view illustrating an example of the movement assist device when applied to ankle joint equipment; 
         FIG. 12  is a perspective view illustrating an example of the movement assist device when applied to shoulder joint equipment; 
         FIG. 13  is a perspective view illustrating an example of the movement assist device when applied to elbow joint equipment; and 
         FIG. 14  is a perspective view illustrating an example of the movement assist device when applied to wrist joint equipment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing. 
     A movement assist device according to a view point of an embodiment includes: a motor including a stator and a rotator; two arm members connected to each of the stator and the rotator and configured to be connected to a predetermined part of a body of an equipped person; a signal acceptor configured to accept a trigger signal that triggers a driving of the motor; and a driving controller configured to drive the motor so that the two arm members expand in response to a trigger that the signal acceptor accepts a first one of the trigger signal. 
     This movement assist device may be a movement assist device that assists movement of an equipped person, for example. 
     A movement assist device according to another view point of the embodiment includes; a motor including a stator and a rotator; two arm members connected to each of the stator and the rotator and configured to be connected to a predetermined part of a body of an equipped person; means for accepting a trigger signal that triggers a driving of the motor; and means for driving the motor so that the two arm members expand in response to a trigger that the means for accepting the trigger signal accepts a first one of the trigger signal. 
     According to the movement assist device of the embodiment, the assist according to the physical function (or the physical state) of the equipped person can be achieved. 
     One embodiment will be described below by referring to the drawings. The present embodiment is an example in which the movement assist device is applied to assist the movement of the hip joint. 
     &lt;General Configuration of the Movement Assist Device&gt; 
     In the examples illustrated in  FIG. 1A  and  FIG. 1B , a movement assist device  1  of the present embodiment assists the movement of a hip joint of an equipped person M who wears hip joint equipment  80  or  80 ′ on a right leg F1. The movement assist device  1  is applicable to both of the two hip joint equipment  80  and  80 ′ illustrated in  FIG. 1A  and  FIG. 1B . It is noted that illustration of a first connector  7  and a second connector  8  is omitted in  FIG. 1A  and  FIG. 1B . 
     The movement assist device  1  has a motor  4 , a first arm member  5 , a second arm member  6 , a sensor unit  30  (see  FIG. 6  described later), a manual switch  20 , a control module  50  (see  FIG. 7  described later), a controller  60  (see  FIG. 7  described later), and a not-shown microphone. The first arm member  5  is connected to a stator  2  of the motor  4 . The second aim member  6  is connected to a rotator  3  of the motor  4 . 
     &lt;Hip Joint Equipment&gt; 
     The hip joint equipment  80  illustrated in  FIG. 1A  is utilized to fix a knee joint, for example. The hip joint equipment  80  includes a waist frame  80   a , a femur frame  80   b , and a cruris frame  80   c . The waist frame  80   a  is attached to the right side of the waist via a waist band B1 mounted around the waist of the equipped person M. The upper end of the femur frame  80   b  is connected to the lower part of the waist frame  80   a  in a rotatable manner by a connection part  80   d  (see  FIG. 3  described later). The femur frame  80   b  is attached along the longitudinal direction of the femur of the right leg F1 via leg bands B2 mounted on two parts, namely, the upper part and the lower part in the femur of the right leg F1. The femur frame  80   b  is revolved with respect to the waist frame  80   a  in response to the walking movement of the equipped person M and therefore is able to expand and bend with respect to the waist frame  80   a . It is noted that the term “expand” refers to the revolution of the femur frame  80   b  (or the relative revolution of the waist frame  80   a  and the femur frame  80   b ) to the direction so that the angle between the waist frame  80   a  and the femur frame  80   b  (the angle of the foreside of the body) increases. In contrast, the term “bend” refers to the revolution of the femur frame  80   b  (or the relative revolution of the waist frame  80   a  and the femur frame  80   b ) to the direction so that the above-described angle decreases. 
     The upper end of the cruris frame  80   c  is connected to the lower end of the femur frame  80   b  by a connection part  80   e . The cruris frame  80   c  is able to be fixed or revolved with respect to the femur frame  80   b . The cruris frame  80   c  is attached along the longitudinal direction of the cruris of the right leg F1 via leg bands B3 mounted on two parts, namely, the upper part and the lower part in the cruris of the right leg F1 of the equipped person M. 
     It is noted that, while the depiction is omitted, the backside of the hip joint equipment  80  is provided with a curve frame made of metal, plastic, or the like partially covering the rear half part of the femur and the cruris. This curve frame supports the lower limb. The front face of this curve frame is fixed by the above-described bands B2, B3, and the like. 
     The hip joint equipment  80 ′ illustrated in  FIG. 1B  is utilized when it is not necessary to fix the knee joint, for example. The hip joint equipment  80 ′ has the same configuration as the above-described hip joint equipment  80  except that it does not have the cruris frame  80   c  of the hip joint equipment  80  as illustrated in  FIG. 1A  and that a short femur frame  80   b ′ is connected to the waist frame  80   a . The femur frame  80   b ′ is attached along the longitudinal direction of the femur of the right leg F1 via a supporter band B4 mounted on the femur of the right leg F1 of the equipped person M. 
     The motor  4 , the first arm member  5 , and the second arm member  6  of the movement assist device  1  form a movement mechanical part attached to the hip joint equipment  80  ( 80 ′). The first arm member  5  is connected to the waist of the equipped person M via the waist frame  80   a  of the hip joint equipment  80  ( 80 ′). The second arm member  6  is connected to the femur of the right leg F1 of the equipped person M via the femur frame  80   b  ( 80   b ′). Further, the sensor unit  30  (see  FIG. 6 ) is arranged to a footwear S1 in the right leg F1 side. The manual switch  20  is arranged to the waist band B1 (the right side of the waist of the equipped person M in the examples illustrated in  FIG. 1A  and  FIG. 1B ). Further, the control module  50  and the controller  60  (see  FIG. 7 ) are accommodated in a control box  15  attached to the waist band B1 (in the foreside of the waist of the equipped person M in the examples illustrated in  FIG. 1A  and  FIG. 1B ). The microphone (not shown) is set to the waist of the equipped person M via the waist band B1, for example. It is noted that the control module  50  and/or the controller  60  may be fixed to other position than the waist of the equipped person M (for example, the chest and the like). 
     &lt;Connection of the Arm Members to the Hip Joint Equipment&gt; 
     As illustrated in  FIG. 2 , the first arm member  5  has a plate-like connection plate  7   a  integrally provided to the first arm member  5  in the intermediate part in the longitudinal direction of the first arm member  5 . The connection plate  7   a  forms one part of the first connector  7  (see  FIG. 3  described later). In the connection plate  7   a , screw holes  9   a  piercing through in the thickness direction are provided in multiple positions (four positions near four corners in this example). One end of the first arm member  5  (the lower side in  FIG. 2 ) is fixed to the stator  2  and the first arm member  5  protrudes above the motor  4 . The first arm member  5  fixed to the stator  2  revolves within a plane substantially vertical to the rotation axis AX1 of the motor  4 . 
     The second arm member  6  has a slider  8   a  for attachment. The slider  8   a  forms one part of the second connector  8  (see  FIG. 3  described later). One end of the second arm member  6  (the upper side in  FIG. 2 ) is fixed to the rotator  3  and the second arm member  6  protrudes in the opposite side of the first arm member  5 . The slider  8   a  is formed in a plate-like shape and mounted to the second arm member  6  so as to be able to move in the longitudinal direction of the second arm member  6 . In the slider  8   a , the screw holes  9   a  piercing through in the thickness direction are provided in multiple positions (four positions near four corners in this example). The second arm member  6  fixed to the rotator  3  revolves within a plane substantially vertical to the rotation axis AX1 of the motor  4 . 
     As illustrated in  FIG. 3 , a connection plate  7   b  forming the other part of the first connector  7  is formed in a plate-like shape similar to the above-described one connection plate  7   a . A recess groove  10   a  for accommodating the waist frame  80   a  is provided on the surface of the other connection plate  7   b  facing the one connection plate  7   a . Further, screw holes  9   b  corresponding to the screw holes  9   a  of the one connection plate  7   a  are provided in multiple positions of the connection plate  7   b  (four positions near four corners in this example). 
     A connection plate  8   b  forming the other part of the second connector  8  is formed in a plate-like shape similar to the above-described slider  8   a . A recess groove  11   a  for accommodating the femur frame  80   b  is provided on the surface of the connection plate  8   b  facing the slider  8   a . Similarly, another recess groove  11   a  for accommodating the second arm member is provided in the surface of the slider  8   a  facing the connection plate  8   b  (see  FIG. 4B ). Further, screw holes  9   b  corresponding to the screw holes  9   a  of the slider  8   a  are provided in multiple positions of the connection plate  8   b  (four positions near four corners in this example). It is noted that, in the second connector  8 , a connection plate may be provided to the second arm member  6 , and a slider may be provided to the femur frame  80   b.    
     As illustrated in  FIG. 4A , the one connection plate  7   a  and the other connection plate  7   b  accommodating the waist frame  80   a  in the recess groove  10   a  are connected to each other by screwing screws  12  from the screw holes  9   a  of the one connection plate  7   a  to the screw holes  9   b  of the other connection plate  7   b . Thereby, the first arm member  5  is fixed to the waist frame  80   a.    
     On the other hand, as illustrated in  FIG. 4B , the slider  8   a  accommodating the second arm member  6  in the recess groove  11   a  and the connection plate  8   b  accommodating the femur frame  80   b  in the recess groove  11   a  are connected to each other by screwing the screws  12  from the screw holes  9   a  of the slider  8   a  to the screw holes  9   b  of the connection plate  8   b . Then, while the femur frame  80   b  and the connection plate  8   b  are fixed to each other, the slider  8   a  and the second arm member  6  are slidable with respect to each other. As described above, the slider  8   a  is connected by the screws  12  to the connection plate  8   b  fixed to the femur frame  80   b . Therefore, the second arm member  6  is slidable with respect to the femur frame  80   b . That is, the second arm member  6  is connected to the femur frame  80   b  in a slidable manner in the longitudinal direction. 
     The above-described connection structure allows the motor  4 , the first arm member  5 , and the second arm member  6  of the movement assist device  1  to be attached to and removed from the hip joint equipment  80  and  80 ′. In this way, in the example illustrated in  FIG. 1A , the first arm member  5  is connected to the waist of the equipped person M via the waist frame  80   a . Furthermore, the second arm member  6  is connected to the femur part of the right leg F1 of the equipped person M via the femur frame  80   b . Further, in the example illustrated in  FIG. 1B , the first arm member  5  is connected to the waist of the equipped person M via the waist frame  80   a . Furthermore, the second arm member  6  is connected to the femur part of the right leg F1 of the equipped person M via the femur frame  80   b′.    
     &lt;Manual Switch&gt; 
     The manual switch  20  is attached to the waist of the equipped person M via the waist band B1 as illustrated in  FIG. 1A  and  FIG. 1B . 
     The manual switch  20  is manually operated by a person who helps the equipped person M (for example, a medical worker such as a physical therapist) when the equipped person M makes a walking movement. This allows for the assist of the walking movement of the equipped person M by the movement assist device  1 . 
     Specifically, the manual switch  20  has a first switch  20   a , a second switch  20   b , and a third switch  20   c , as illustrated in  FIG. 5 . When manually operated, the first switch  20   a  and the second switch  20   b  are configured to output the trigger signal that triggers the driving of the motor  4 . Among the above, the first switch  20   a  functions as a kick-out switch for assisting the kick-out movement by the right leg F1 of the equipped person M. The first switch  20   a  outputs a first trigger signal. This first trigger signal is a signal for driving the motor  4  so that the two arm members  5  and  6  expand (that is, driving the motor  4  so that the motor  4  rotates in the direction to cause the two arm members  5  and  6  to expand). The second switch  20   b  functions as a shake-out switch for assisting the shake-out movement by the right leg F1 of the equipped person M. The second switch  20   b  outputs a second trigger signal. This second trigger signal is a signal for driving the motor  4  so that the two arm members  5  and  6  bend (that is, driving the motor  4  so that the motor  4  rotates in the direction to cause the two arm members  5  and  6  to bend). The third switch  20   c  functions as a stop switch. For example, the equipped person M manually operates the third switch  20   c  when stopping its both legs (the right leg F1 and a left leg F2). Thereby, the third switch  20   c  outputs a trigger signal for causing the motor  4  to stop driving. 
     It is noted that the term “expand” of the arm members  5  and  6  refers to the revolution of the second arm member  6  (or the relative revolution of the first arm member  5  and the second arm member  6 ) to the direction so that the angle between the first arm member  5  and the second arm member  6  (the angle between the waist frame  80   a  and the femur frame  80   b ) increases. In contrast, the term “bend” refers to the revolution of the second arm member  6  (or the relative revolution of the first arm member  5  and the second arm member  6 ) to the direction so that the above-described angle decreases. 
     &lt;Microphone&gt; 
     A not-shown microphone is attached to the waist of the equipped person M via the waist band B1, for example. It is noted that the microphone may be fixed to other position than the waist of the equipped person M (for example, the chest and the like). 
     The voice of the person who helps the equipped person M is inputted to the microphone when the equipped person M makes a walking movement. The voice to be inputted may include, for example, the voice expressing the movement such as “kick-out”, “shake-out”, or the like, the call such as “one two, one two”, and the hand clapping sound. 
     &lt;Sensor Unit&gt; 
     The sensor unit  30  is set to an insole I1 of the footwear S1 of the right leg F1 side (see  FIG. 1A ) as illustrated in  FIG. 6 . It is noted that the sensor unit  30  may be set to other position of the footwear S1 than the insole I1 (for example, a shoe sole and the like). The sensor unit  30  has a first pressure-sensitive sensor  31   a , a fixed resistor  32 , a second pressure-sensitive sensor  31   b , and a fixed resistor  33 . 
     The first pressure-sensitive sensor  31   a  is set to the position in the insole I1 corresponding to the thenar eminence of the sole of the right leg F1. It is noted that the first pressure-sensitive sensor  31   a  may be set to the position in the insole I1 corresponding to other part than the thenar eminence of the sole of the right leg F1. The resistance of the first pressure-sensitive sensor  31   a  changes depending on the force (the pressure) applied to the position corresponding to the thenar eminence of the sole of the right leg F1. This allows the first pressure-sensitive sensor  31   a  to detect the force applied to that thenar eminence. In this example, as the first pressure-sensitive sensor  31   a , used is a pressure-sensitive sensor in which the resistance increases according to the increase in the force applied to the position corresponding to the thenar eminence of the sole of the right leg F1. It is noted that, as the first pressure-sensitive sensor  31   a , used may be a pressure-sensitive sensor in which the resistance decreases according to the increase in the force applied to the position corresponding to the thenar eminence of the sole of the right leg F1. The fixed resistor  32  has substantially a constant resistance and is connected in series to the first pressure-sensitive sensor  31   a . That is, when substantially a constant voltage is applied to the first pressure-sensitive sensor  31   a  and the fixed resistor  32 , the ratio between the resistance of the first pressure-sensitive sensor  31   a  and the resistance of the fixed resistor  32  changes depending on the force applied to the first pressure-sensitive sensor  31   a . As a result, the voltage of the connection node of the first pressure-sensitive sensor  31   a  and the fixed resistor  32  changes. This voltage is inputted to a microcontroller  36  (described later) of a sensor module  35  as an output voltage Vout1 representing the detection result by the first pressure-sensitive sensor  31   a . The sensor module  35  is set to the position in the footwear S1 corresponding to the instep of the right leg F1, for example. 
     The second pressure-sensitive sensor  31   b  is set to the position in the insole I1 corresponding to the heel of the sole of the right leg F1. It is noted that the second pressure-sensitive sensor  31   b  may be set to the position in the insole I1 corresponding to other part than the heel of the sole of the right leg F1. The resistance of the second pressure-sensitive sensor  31   b  changes depending on the force (the pressure) applied to the position corresponding to the heel of the sole of the right leg F1. This allows the second pressure-sensitive sensor  31   b  to detect the force applied to that heel. In this example, as the second pressure-sensitive sensor  31   b , used is a pressure-sensitive sensor in which the resistance increases according to the increase in the force applied to the position corresponding to the heel of the sole of the right leg F1. It is noted that, as the second pressure-sensitive sensor  31   a , used may be a pressure-sensitive sensor in which the resistance decreases according to the increase in the force applied to the position corresponding to the heel of the sole of the right leg F1. The fixed resistor  33  has substantially a constant resistance and is connected in series to the second pressure-sensitive sensor  31   b . That is, when substantially a constant voltage is applied to the second pressure-sensitive sensor  31   b  and the fixed resistor  33 , the ratio between the resistance of the second pressure-sensitive sensor  31   b  and the resistance of the fixed resistor  33  changes depending on the force applied to the second pressure-sensitive sensor  31   b . As a result, the voltage of the connection node of the second pressure-sensitive sensor  31   b  and the fixed resistor  33  changes. This voltage is inputted to the microcontroller  36  (described later) of the sensor module  35  as an output voltage Vout2 representing the detection result by the second pressure-sensitive sensor  31   b.    
     It is noted that, hereafter, the first pressure-sensitive sensor  31   a  and the second pressure-sensitive sensor  31   b  are collectively referred to as a pressure-sensitive sensor  31 . 
     &lt;Functional Configuration of the Sensor Module and the Control Module&gt; 
     Next, the conceptual functional configuration of the sensor module  35  and the control module  50  will be described below by referring to  FIG. 7 . 
     As illustrated in  FIG. 7 , the sensor module  35  has the microcontroller  36 , an antenna  37  for radio communication with the above-described control module  50  (for transmitting information to the control module  50 ), and a battery for the driving power supply (not shown). 
     The microcontroller  36  is inputted with the output voltage Vout1 representing the detection result of the first pressure-sensitive sensor  31   a  and the output voltage Vout2 representing the detection result of the second pressure-sensitive sensor  31   b.    
     Here, the applied voltage is denoted as Vin, the resistance of the first pressure-sensitive sensor  31   a  is denoted as R 1 , and the resistance of the fixed resistor  32  is denoted as R 2 , and the output voltage Vout1 is expressed by the following equation (1). 
       Vout1=Vin· R 2/( R 1 +R 2)  (1)
 
     As described above, as the first pressure-sensitive sensor  31   a , used is the pressure-sensitive sensor in which the resistance increases according to the increase in the force applied to the position corresponding to the thenar eminence of the sole of the right leg F1. Therefore, in response to the increase of the force applied to the position corresponding to the thenar eminence, the resistance R 1  of the first pressure-sensitive sensor  31   a  increases and thus the output voltage Vout1 decreases. 
     Also, the applied voltage is denoted as Vin, the resistance of the second pressure-sensitive sensor  31   b  is denoted as R 3 , and the resistance of the fixed resistor  33  is denoted as R 4 , and the output voltage Vout2 is expressed by the following equation (2). 
       Vout2=Vin· R 4/( R 3 +R 4)  (2)
 
     As described above, as the second pressure-sensitive sensor  31   b , used is the pressure-sensitive sensor in which the resistance increases according to the increase in the force applied to the position corresponding to the heel of the sole of the right leg F1. Therefore, in response to the increase of the force applied to the position corresponding to the heel, the resistance R 3  of the second pressure-sensitive sensor  31   b  increases and thus the output voltage Vout2 decreases. 
     Further, when the value of the output voltage Vout1 is less than or equal to a threshold and the value of the output voltage Vout2 is less than or equal to a threshold, the microcontroller  36  determines that the force applied to (the thenar eminence and the heel of) the right leg F1 is greater than or equal to a desired value (a predetermined value), that is, the shoe sole of the footwear S1 is in contact with the ground at a proper force. Therefore, when the value of the output voltage Vout1 is less than or equal to the threshold (that is, the first pressure-sensitive sensor  31   a  is ON) and the value of the output voltage Vout2 is less than or equal to the threshold (that is, the second pressure-sensitive sensor  31   b  is ON), the microcontroller  36  outputs the first trigger signal. 
     On the other hand, when the value of the output voltage Vout1 is greater than the threshold and the value of the output voltage Vout2 is greater than the threshold, the microcontroller  36  determines that the force applied to (the thenar eminence and the heel of) the right leg F1 is less than the desired value (the predetermined value), that is, the shoe sole of the footwear S1 is floating. Therefore, when the value of the output voltage Vout1 is greater than the threshold (that is, the first pressure-sensitive sensor  31   a  is OFF) and the value of the output voltage Vout2 is greater than the threshold (that is, the second pressure-sensitive sensor  31   b  is OFF), the microcontroller  36  outputs the second trigger signal. 
     It is noted that, in the present embodiment, the first trigger signal is outputted when both values of the output voltage Vout1 and the output voltage Vout2 are less than or equal to the thresholds, and the second trigger signal is outputted when both values are greater than the thresholds. Instead, the first trigger signal may be outputted when one of the values of the output voltage Vout1 and the output voltage Vout2 (for example, the output voltage Vout2 of the heel side) is less than or equal to the threshold, and the second trigger signal may be outputted when this value is greater than the threshold. 
     Further, the microcontroller  36  transmits the first trigger signal and the second trigger signal to the control module  50  by the radio communication via the antenna  37 . 
     The control module  50  is connected to the sensor module  35  so as to be able to perform radio communication. Furthermore, the control module  50  is communicably connected to the controller  60  via the cable. It is noted that the control module  50  may be communicably connected to the sensor module  35  via the cable and connected to the controller  60  so as to be able to perform radio communication. The control module  50  controls the controller  60  based on the detection result of the sensor  31  received by the radio communication with the sensor module  35  (the details will be described later). 
     Further, the controller  60  is communicably connected to the motor  4  via a not-shown cable. It is noted that the controller  60  may be connected to the motor  4  so as to be able to perform radio communication. The controller  60  performs the driving control of the motor  4  based on the control signal inputted from the control module  50 . 
     As illustrated in  FIG. 7 , the control module  50  has an antenna  51  for performing radio communication with the sensor module  35  (receiving information from the sensor module  35 ), a microcontroller  52 , and a battery of the driving power supply (not shown). The microcontroller  52  has a signal acceptor  53 , a voice input unit  54 , and a mode selector  55 . 
     The voice input unit  54  is configured to output the first trigger signal and the second trigger signal that correspond to the voice inputted to the above-described microphone. For example, the voice input unit  54  outputs the first trigger signal in response to the utterance “kick-out” and outputs the second trigger signal in response to the utterance “shake-out”. Further, for example, the voice input unit  54  outputs the first trigger signal in response to “one” in the call “one two, one two” and outputs the second trigger signal in response to “two”. Further, for example, the voice input unit  54  outputs the first trigger signal in response to the odd-numbered hand clapping sound and outputs the second trigger signal in response to the even-numbered hand clapping sound. 
     The signal acceptor  53  receives the trigger signal transmitted from the sensor module  35  by the radio communication via the antenna  51  to accept this trigger signal. Further, the signal acceptor  53  accepts the trigger signal outputted from the switch  20  by the manual operation by the helper. Further, the signal acceptor  53  accepts the trigger signal outputted from the audio input  54  in response to the voice inputted to the microphone. The signal acceptor  53  corresponds to an example of the means for accepting the trigger signal. 
     The mode selector  55  selects one of the trigger signals that is to be accepted by the signal acceptor  53  in accordance with the operation of the not-shown selection switch and the like. That is, the mode selector  55  is configured to select any one of a “switch mode” in which the trigger signal by the manual switch  20  is used, a “voice mode” in which the trigger signal by the voice is used, and a “sensor mode” in which the trigger signal by the sensor  31  is used. When the “switch mode” is selected by the mode selector  55 , the signal acceptor  53  accepts the trigger signal from the manual switch  22 , while does not accept the trigger signals from the voice input unit  54  and the sensor module  35 . The similar is applied when other mode is selected. 
     Upon accepting the trigger signal from the sensor module  35 , from the manual switch  20 , or from the voice input unit  54 , the signal acceptor  53  outputs the accepted trigger signal to the controller  60 . 
     The controller  60  has a driving controller  61  and a battery (not shown) for the driving power supply. The driving controller  61  is inputted with the trigger signal from the signal acceptor  53  and performs the driving control of the motor  4  based on the inputted trigger signal. Specifically, when inputted with the first trigger signal, the driving controller  61  drives the motor  4  so that the first arm member  5  and the second arm member  6  expand (that is, drives the motor  4  so that the motor  4  rotates in the direction to cause the two arm members  5  and  6  to expand). Further, when inputted with the second trigger signal, the driving controller  61  drives the motor  4  so that the first arm member  5  and the second arm member  6  bend (that is, drives the motor  4  so that the motor  4  rotates in the direction to cause the two arm members  5  and  6  to bend). The driving controller  61  corresponds to an example of the means for driving the motor. 
     &lt;Operation of the Movement Assist Device&gt; 
     When the “switch mode” is selected by the mode selector  55 , the helper assists the walking movement of the equipped person M by operating the manual switch  20 . In response to the operation of the first switch  20   a , the first trigger signal is outputted from the manual switch  20  to the signal acceptor  53 . In response, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. As a result, the movement assist device  1  assists the kick-out movement of the right leg F1 of the equipped person M. On the other hand, in response to the operation of the second switch  20   b , the second trigger signal is outputted from the manual switch  20  to the signal acceptor  53 . In response, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  bend. As a result, the movement assist device  1  assists the shake-out movement of the right leg F1 of the equipped person M. Therefore, by that the helper operates the first switch  20   a  and the second switch  20   b  of the manual switch  20  alternately at a proper timing, the movement assist device  1  alternately assists the kick-out movement and the shake-out movement of the right leg F1 of the equipped person M to assist the walking movement of the equipped person M. It is noted that, when stopping the assist, the helper operates the third switch  20   c . Thereby, the trigger signal for causing the motor  4  to stop driving is outputted to the signal acceptor  53 . In response, the driving controller  61  stops the driving of the motor  4 . 
     When the “voice mode” is selected by the mode selector  55 , the helper assists the walking movement of the equipped person M by the voice. In response that the voice corresponding to the kick-out operation (the voice of “kick-out”, the voice of “one”, the odd-numbered hand clapping sound, and the like) is inputted to the microphone, the first trigger signal is outputted from the voice input unit  54  to the signal acceptor  53 . In response, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. As a result, the movement assist device  1  assists the kick-out movement of the right leg F1 of the equipped person M. On the other hand, in response that the voice corresponding to the shake-out operation (the voice of “shake-out”, the voice of “two”, the even-numbered hand clapping sound, and the like) is inputted to the microphone, the second trigger signal is outputted from the voice input unit  54  to the signal acceptor  53 . In response, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  bend. As a result, the movement assist device  1  assists the shake-out movement of the right leg F1 of the equipped person M. Therefore, by that the helper inputs the voice corresponding to the kick-out or the shake-out to the microphone alternately at a proper timing, the movement assist device  1  alternately assists the kick-out movement and the shake-out movement of the right leg F1 of the equipped person M to assist the walking movement of the equipped person M. 
     When the “sensor mode” is selected by the mode selector  55 , the assist without the helper is allowed. It is noted that the helper may assist the walking movement of the equipped person M by controlling the contact to the ground of the footwear S1 of the equipped person M. As described above, when the shoe sole of the footwear S1 contacts with the ground at a proper force (when the first pressure-sensitive sensor  31   a  is ON and the second pressure-sensitive sensor  31   b  is ON), the first trigger signal is outputted from the microcontroller  36  to the signal acceptor  53 . In response, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. As a result, the movement assist device  1  assists the kick-out movement of the right leg F1 of the equipped person M. On the other hand, when the shoe sole of the footwear S1 floats from the ground (when the first pressure-sensitive sensor  31   a  is OFF and the second pressure-sensitive sensor  31   b  is OFF), the second trigger signal is outputted from the microcontroller  36  to the signal acceptor  53 . In response, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  bend. As a result, the movement assist device  1  assists the shake-out movement of the right leg F1 of the equipped person M. When the equipped person M walks, the movements of grounding of the right leg F1, kick-out of the right leg F1 (floating, shake-out, grounding, and kick-out of the left leg F2), floating of the right leg F1, shake-out of the right leg F1, and grounding of the right leg F1 are repeated. By the above-described movement control, the movement assist device  1  alternately assists the kick-out movement and the shake-out movement of the right leg F1 of the equipped person M to assist the walking movement of the equipped person M. 
     Advantages of the Embodiment 
     As described above, the movement assist device  1  of the present embodiment has the motor  4 , the two arm members  5  and  6 , the signal acceptor  53 , and the driving controller  61 . In response to the trigger that the signal acceptor  53  accepts the first trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. 
     This allows for adjustment of the operating timing of the motor  4  in accordance with the physical function (or the physical state) of the equipped person M by outputting the first trigger signal to the signal acceptor  53  at a proper timing. Therefore, the assist according to the physical function of the equipped person can be achieved. 
     Further, the expanding movement of the two arm members  5  and  6  corresponds to the kick-out movement when the movement assist device  1  is applied to the hip joint as seen in the present embodiment. In the walking movement, the kick-out is an important movement accompanied by a weight movement. Therefore, the adjustable timing of the kick-out movement allows for a more effective assist to the equipped person. 
     Further, in the present embodiment, in particular, in response to the trigger that the signal acceptor  53  accepts the second trigger signal, the driving controller  61  drives the motor so that the two arm members  5  and  6  bend. This allows for adjustment of the operation timing of the motor  4  for both expanding movement and the bending movement of the two arm members  5  and  6 . This can further enhance the adaptation to the physical function of the equipped person. 
     Further, in the present embodiment, in particular, the motor  4  and the two arm members  5  and  6  is attachable to and removable from the hip joint equipment  80  and  80 ′ used by the equipped person M. This allows for the following advantages. Specifically, in general, the equipment mounted with the actuator such as the motor is configured in an integrated manner. In this case, it cannot uniquely support the equipped persons M having the different physiques. This causes insufficient fitting ability of the equipment. Furthermore, there is likelihood that the function cannot be sufficiently performed due to the nonconformity of the equipment. Moreover, since it becomes difficult to use the existing equipment, which requires a purchase of new whole equipment and thus the cost increases. Furthermore, when it is used, the removal and attachment of the entire equipment are needed. Moreover, it takes more time and cost for the repairing and maintenance. In contrast, in the present embodiment, the above-described configuration allows for the use of the existing equipment that the equipped person M usually uses. Therefore, the movement assist device  1  of the present embodiment has a high fitting property and the equipped person is thus able to use the equipment fitted to its physique to obtain a sufficient assist of the motor driving. Further, the existing equipment can be utilized, which allows for the high versatility and the reduction in the cost. Further, the attachment and removal of the motor  4  and the arm members  5  and  6  only are needed for use, that is, the removal and attachment of the equipment are unnecessary, which can improve the convenience at the equipped person. Moreover, the repairing and the maintenance can be simplified. 
     Further, in the present embodiment, in particular, the movement assist device  1  has the switches  20   a  and  20   b  configured to output the first trigger signal and the second trigger signal according to the manual operation. This allows the helper assisting the equipped person M, for example, the medical worker such as the physical therapist to use the switches  20   a  and  20   b  to adjust the operation timing of the motor  4  by the manual operation. Therefore, the helper is able to perform the assist that is more suitable to the physical function of the equipped person. 
     Further, in the present embodiment, in particular, the movement assist device  1  has the voice input unit  54  configured to output the first trigger signal and the second trigger signal according to the inputted voice. This allows the helper to adjust the operation timing of the motor by the utterance, the hand clapping sound, and the like. Therefore, the helper is able to perform the assist that is more suitable to the physical function of the equipped person M. 
     Further, in the present embodiment, in particular, the movement assist device  1  has the sensor  31  configured to detect the force applied to the sole of the equipped person M and outputs the first trigger signal and the second trigger signal according to the detection result. Further, the sensor  31  outputs the first trigger signal to cause the two arm members  5  and  6  to expand when the sensor  31  detects the grounding of the right leg F1, thereby the movement assist device  1  assists the kick-out movement. On the other hand, the sensor  31  outputs the second trigger signal to cause the two arm members  5  and  6  to bend when the sensor  31  detects the floating of the right leg F1, thereby the movement assist device  1  assists the shake-out movement. This allows for the adjustment of the operating timing of the motor  4  according to the movement state of the right leg F1 of the equipped person M. Therefore, the walking assist that is more suitable to the physical function of the equipped person M can be achieved. 
     Further, in the present embodiment, in particular, the first connector  7  ( 7   a ,  7   b ) and the second connector  8  ( 8   a ,  8   b ) are used to connect the two arm members  5  and  6  to the corresponding parts of the hip joint equipment  80  of the equipped person M. The second connector  8  connects the arm member  6  to the femur frame  80   b  so that the arm member  6  and the femur frame  80   b  are slidable with respect to each other along the longitudinal direction. Thereby, even when the rotation axis AX1 of the motor  4  and the joint axis AX2 of the connection part  80   d  of the femur frame  80   b  ( FIG. 3 ) are slightly shifted to each other, the displacement of the arm member  6  to the connection part (equipment)  80   d  during revolving operation due to this axial shift can be absorbed by the relative slide of the arm member  6  and the femur frame  80   b  and thus the assist by the motor  4  can be performed. 
     Further, in the present embodiment, in particular, the movement assist device  1  has the manual switch  20 , the voice input unit  54 , and the sensor  31 . The mode selector  55  selects any one of the “switch mode” in which the trigger signal by the manual switch  20  is used, the “voice mode” in which the trigger signal by the voice is used, and the “sensor mode” in which the trigger signal by sensor  31  is used. This allows for the selection of the proper “mode” according to the physical function of the equipped person M, the usage environment of the movement assist device  1 , and so on. This can enhance the adaptation to the equipped person M and improve the convenience. 
     It is noted that, in the above-described embodiment, the movement assist device  1  is applied to the walking assist of the equipped person M who wears the hip joint equipment  80  on its one of the legs (the right leg F1 in the above-described example). However, without limitation, the movement assist device  1  may be applied to the equipped person who wears the equipment on its both legs, for example. Further, either one of the first pressure-sensitive sensor  31   a  and the second pressure-sensitive sensor  31   b  may be set as the sensor. 
     Modified Examples 
     It is noted that the embodiment is not limited to the above. Various modifications are possible within the scope not departing from its spirit and technical concept. Such modified examples will be described below. 
     (1) The Case where the Pressure-Sensitive Sensors are Arranged to Both Legs 
     While the sensor  31  is set to the right leg F1 of the equipped person M in the above-described embodiment, both legs of the equipped person M may be provided with the sensor. In this case, the signal acceptor  53  may control the motor driving to stop in response to the trigger that the first trigger signals are accepted from both of the two sensors. 
       FIG. 8  illustrates an example of the configuration of the sensor units for both legs in the present modified example. As illustrated in  FIG. 8 , a sensor unit  40  is provided to the left leg F2 of the equipped person M similarly to the right leg F1 provided with the sensor unit  30 . The sensor unit  40  is set to an insole I2 of the footwear of the left leg F2. The sensor unit  40  is configured similarly to the sensor unit  30 , and has a first pressure-sensitive sensor  41   a , a fixed resistor  42 , a second pressure-sensitive sensor  41   b , and a fixed resistor  43 . 
     An output voltage Vout3 outputted by the first pressure-sensitive sensor  41   a  and an output voltage Vout4 outputted by the second pressure-sensitive sensor  41   b  are inputted to a microcontroller  46  of a sensor module  45 . 
     When the values of the inputted output voltages Vout3 and Vout4 are less than or equal to a threshold, the microcontroller  46  determines that the shoe sole of the left leg F2 is in contact with the ground at a proper force, and outputs the first trigger signal. On the other hand, when the values of the output voltages Vout3 and Vout4 are greater than the threshold, the microcontroller  46  determines that the shoe sole of the left leg F2 is floating, and outputs the second trigger signal. 
       FIG. 9  illustrates the functional configuration of the movement assist device  1  in the present modified example. The functional block diagram illustrated in  FIG. 9  is similar to the functional block diagram illustrated in  FIG. 7  except that the pressure-sensitive sensor  41  and the sensor module  45  are added, that a condition setter  56  is added to the control module  50 , and that a driving stopper  62  is added to the controller  60 . 
     The driving stopper  62  is configured to stop the driving of the motor  4  in response to the trigger that the signal acceptor  53  accepts the first trigger signals from both of the pressure-sensitive sensor  31  and the pressure sensitive sensor  41 . That is, under the selection of the “sensor mode” by the mode selector  55 , upon accepting the first trigger signals from both of the first sensor  31  and the second sensor  41 , the signal acceptor  53  outputs the first trigger signal and the second trigger signal to the controller  60 . As a result, the driving stopper  62  stops the driving of the motor  4 . 
     Thereby, it can be suppressed that the movement assist device  1  erroneously continues the walking assist when the equipped person M stops walking and has both legs F1 and F2 contact to the ground. Therefore, the movement assist device  1  is able to implement the proper walking assist according to the intention of the equipped person M. 
     Further, the condition setter  56  is configured to set the condition under which the driving stopper  62  stops the driving of the motor  4 . That is, even when the equipped person M stops walking and has both legs F1 and F2 contact to the ground, there is likelihood that the distribution of the weight in the sole is different between the left and right legs due to the custom and the habit of the equipped person M. For example, in the case where the equipped person M stops walking in a position close to tiptoe standing, there may be a case where the weight is unlikely to be applied to the heels. In contrast, in the case where the equipped person M stops walking with substantially applying its weight on the heels only and substantially floating its tiptoes, there may be a case where the weight is unlikely to be applied to the tiptoes. In order to address such cases, the condition setter  56  sets the condition under which the driving stopper  62  stops the driving of the motor  4 . 
     For example, when the equipped person M is the person who stops walking in the position close to tiptoe standing as described above, the condition setter  56  may set the condition so that the driving of the motor  4  stops in response to the trigger that both ON signals from the first pressure-sensitive sensors  31   a  and  41   a  are accepted. On the other hand, when the equipped person M is the person who stops walking with substantially applying its weight on the heels only and substantially floating its tiptoes as described above, the condition setter  56  may set the condition so that the driving of the motor  4  stops in response to the trigger that both ON signals from the second pressure-sensitive sensors  31   b  and  41   b  are accepted. This allows for the walking assist by changing the condition even in the above-described cases. Therefore, the adaptation to the equipped person M can be further enhanced. 
     (2) The Case where the Movement Assist Device is Applied to Knee Joint Equipment 
     The present modified example is an example when the movement assist device  1  is applied to knee joint equipment.  FIG. 10  illustrates an example of the present modified example. 
     As illustrated in  FIG. 10 , knee joint equipment  82  has a femur frame  82   a  extending along the thigh from the knee and a cruris frame  82   b  extending along the cruris from the knee in the right side of the right leg F1 of the equipped person M. The femur frame  82   a  is attached along the right side of the femur via two femur bands B5 mounted on the femur of the equipped person M. The upper end of the cruris frame  82   b  is connected to the lower end of the femur frame  82   a , and the cruris frame  82   b  is able to revolve with respect to the femur frame  82   a . The cruris frame  82   b  is attached along the longitudinal direction of the cruris via a support band B6 mounted under the knee of the cruris. 
     It is noted that, in the present modified example, the term “expand” refers to the revolution of the cruris frame  82   b  (the second arm member  6 ) (or the relative revolution of the femur frame  82   a  (the first arm member  5 ) and the cruris frame  82   b  (the second arm member  6 )) to the direction so that the angle between the femur frame  82   a  and the cruris frame  82   b  (the angle of the backside of the body) increases. In contrast, the term “bend” refers to the revolution of the cruris frame  82   b  (the second arm member  6 ) (or the relative revolution of the femur frame  82   a  (the first arm member  5 ) and the cruris frame  82   b  (the second arm member  6 )) to the direction so that the above-described angle decreases. 
     The first arm member  5  of the movement assist device  1  is connected to the femur of the right leg F1 of the equipped person M via the femur frame  82   a  of the knee joint equipment  82 . The second arm member  6  is connected to the cruris of the right leg F1 via the cruris frame  82   b . In the present modified example, the motor  4 , the first arm member  5 , and the second arm member  6  of the movement assist device  1  are configured to be attachable to and removable from the existing knee joint equipment  82  by the connection structure similar to the above-described embodiment. 
     Other configuration of the present modified example is basically similar to the above-described embodiment. That is, in response to the trigger that the signal acceptor  53  accepts the first trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. In response to the trigger that the signal acceptor  53  accepts the second trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  bend. It is noted that the condition under which the microcontroller  36  outputs the first trigger signal and the second trigger signal under the “sensor mode” can be properly changed according to the configuration of the present modified example. 
     Therefore, the assist according to the physical function of the equipped person can be achieved and thus the advantages similar to the above-described embodiments can be obtained. 
     (3) The Case where the Movement Assist Device is Applied to Ankle Joint Equipment 
     The present modified example is an example when the movement assist device  1  is applied to ankle joint equipment.  FIG. 11  illustrates an example of the present modified example. 
     As illustrated in  FIG. 11 , ankle joint equipment  84  has a cruris frame  84   a  extending along the cruris from the ankle and an instep frame  84   b  extending along the side of the instep from the ankle in the right side of the right leg F1 of the equipped person M. The cruris frame  84   a  is attached along the right side from the ankle of the cruris via a cruris band B7 mounted on the cruris. One end of the instep frame  84   b  is connected to the lower end of the cruris frame  84   a , and the instep frame  84   b  is able to revolve with respect to the cruris frame  84   a . While the instep frame  84   b  is arranged inside the footwear S1 in this example, it may be arranged outside of the footwear S1. 
     It is noted that, in the present modified example, the term “expand” refers to the revolution of the instep frame  84   b  (the second arm member  6 ) (or the relative revolution of the cruris frame  84   a  (the first arm member  5 ) and the instep frame  84   b  (the second arm member  6 )) to the direction so that the angle between the cruris frame  84   a  and the instep frame  84   b  (the angle of the foreside of the body) increases. In contrast, the term “bend” refers to the revolution of the instep frame  84   b  (the second arm member  6 ) (or the relative revolution of the cruris frame  84   a  (the first arm member  5 ) and the instep frame  84   b  (the second arm member  6 )) to the direction so that the above-described angle decreases. 
     The first arm member  5  of the movement assist device  1  is connected to the cruris of the right leg F1 of the equipped person M via the instep frame  84   a  of the ankle joint equipment  84 . The second arm member  6  is connected to the instep of the right leg F1 via the instep frame  84   b . In the present modified example, the motor  4 , the first arm member  5 , and the second arm member  6  of the movement assist device  1  are configured to be attachable to and removable from the existing ankle joint equipment  84  by the connection structure similar to the above-described embodiment. 
     Other configuration of the present modified example is basically similar to the above-described embodiment. That is, in response to the trigger that the signal acceptor  53  accepts the first trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. In response to the trigger that the signal acceptor  53  accepts the second trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  bend. It is noted that the condition under which the microcontroller  36  outputs the first trigger signal and the second trigger signal under the “sensor mode” can be properly changed according to the configuration of the present modified example. 
     Therefore, the assist according to the physical function of the equipped person can be achieved and thus the advantages similar to the above-described embodiments can be obtained. 
     (4) The Case where the Movement Assist Device is Applied to Shoulder Joint Equipment 
     The present modified example is an example when the movement assist device  1  is applied to shoulder joint equipment.  FIG. 12  illustrates an example of the present modified example. 
     As illustrated in  FIG. 12 , shoulder joint equipment  86  has an upper shoulder frame  86   a  curving and extending along the upper shoulder from the corner of the right shoulder of the equipped person M and an upper arm frame  86   b  extending along the upper arm from the corner. The upper shoulder frame  86   a  is fixed to the support T-shirts T put on the bust of the equipped person M via a not-shown attachment member. The upper end of the upper arm frame  86   b  is connected to the lower end of the upper shoulder frame  86   a , and the upper arm frame  86   b  is able to revolve with respect to the upper shoulder frame  86   a . The upper aim frame  86   b  is attached along the upper arm from the corner of the shoulder via upper arm bands B8 mounted on two parts, namely, the upper and lower parts of the upper arm. 
     It is noted that, in the present modified example, the term “expand” refers to the revolution of the upper arm frame  86   b  (the second arm member  6 ) (or the relative revolution of the upper shoulder frame  86   a  (the first arm member  5 ) and the upper arm frame  86   b  (the second arm member  6 )) to the direction so that the angle between the upper shoulder frame  86   a  and the upper arm frame  86   b  (the angle of the foreside of the body) increases. In contrast, the term “bend” refers to the revolution of the upper arm frame  86   b  (the second arm member  6 ) (or the relative revolution of the upper shoulder frame  86   a  (the first arm member  5 ) and the upper arm frame  86   b  (the second arm member  6 )) to the direction so that the above-described angle decreases. 
     The first arm member  5  of the movement assist device  1  is formed in a shape having a curve along the upper shoulder frame  86   a . The first arm member  5  of the movement assist device  1  is connected to the right shoulder of the equipped person M via the upper shoulder frame  86   a  of the shoulder joint equipment  86 . The second arm member  6  is connected to the upper arm via the upper arm frame  86   b . Also in the present modified example, the motor  4 , the first arm member  5 , and the second arm member  6  of the movement assist device  1  are configured to be attachable to and removable from the existing shoulder joint equipment  86  by the connection structure similar to the above-described embodiment. 
     Other configuration of the present modified example is basically similar to the above-described embodiment. That is, in response to the trigger that the signal acceptor  53  accepts the first trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. In response to the trigger that the signal acceptor  53  accepts the second trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  bend. It is noted that, in the present modified example, the “switch mode” or the “voice mode” is selected, but the “sensor mode” is not selected. 
     Therefore, the assist according to the physical function of the equipped person can be achieved and thus the advantages similar to the above-described embodiments can be obtained. 
     (5) The Case where the Movement Assist Device is Applied to Elbow Joint Equipment 
     The present modified example is an example when the movement assist device is applied to elbow joint equipment.  FIG. 13  illustrates an example of the present modified example. 
     As illustrated in  FIG. 13 , elbow joint equipment  88  has an upper arm frame  88   a  extending along the upper arm from the elbow of the right arm A1 of the equipped person M and a forearm frame  88   b  extending along the forearm from the elbow. The upper arm frame  88   a  is attached along the upper arm via upper arm bands B9 mounted on two parts, namely, the upper and lower parts of the upper arm of the right arm A1. The upper end of the forearm frame  88   b  is connected to the lower end of the upper arm frame  88   a , and the forearm frame  88   b  is able to revolve with respect to the upper arm frame  88   a . The forearm frame  88   b  is attached along the forearm via forearm bands B10 mounted on two parts, namely, the upper and lower parts of the forearm. 
     It is noted that, in the present modified example, the term “expand” refers to the revolution of the forearm frame  88   b  (the second arm member  6 ) (or the relative revolution of the upper arm frame  88   a  (the first arm member  5 ) and the forearm frame  88   b  (the second arm member  6 )) to the direction so that the angle between the upper arm frame  88   a  and the forearm frame  88   b  (the angle of the foreside of the body) increases. In contrast, the term “bend” refers to the revolution of the forearm frame  88   b  (the second arm member  6 ) (or the relative revolution of the upper arm frame  88   a  (the first arm member  5 ) and the forearm frame  88   b  (the second arm member  6 )) to the direction so that the above-described angle decreases. 
     The first arm member  5  of the movement assist device  1  is connected to the upper arm of the right arm A1 of the equipped person M via the upper arm frame  88   a  of the elbow joint equipment  88 . The second arm member  6  is connected to the forearm of the right arm A1 via the forearm frame  88   b . Also in the present modified example, the motor  4 , the first arm member  5 , and the second arm member  6  of the movement assist device  1  are configured to be attachable to and removable from the existing elbow joint equipment  88  by the connection structure similar to the above-described embodiment. 
     Other configuration of the present modified example is basically similar to the above-described embodiment. That is, in response to the trigger that the signal acceptor  53  accepts the first trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. In response to the trigger that the signal acceptor  53  accepts the second trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  bend. It is noted that, in the present modified example, the “switch mode” or the “voice mode” is selected, but the “sensor mode” is not selected. 
     Therefore, the assist according to the physical function of the equipped person can be achieved and thus the advantages similar to the above-described embodiments can be obtained. 
     (6) The Case where the Movement Assist Device is Applied to Wrist Joint Equipment 
     The present modified example is an example when the movement assist device is applied to wrist joint equipment.  FIG. 14  illustrates an example of the present modified example. 
     As illustrated in  FIG. 14 , wrist joint equipment  90  has a forearm frame  90   a  extending along the forearm from the wrist in the inside of the left arm A2 of the equipped person M and a wrist frame  90   b  extending from the wrist to the side of the thumb. The forearm frame  90   a  is attached along the forearm via forearm bands B11 mounted on two parts, namely, the upper and lower parts of the forearm. One end of the wrist frame  90   b  is connected to one end of the forearm frame  90   a , and the wrist frame  90   b  is able to revolve with respect to the forearm frame  90   a . The wrist frame  90   b  is attached along the side from the wrist to the thumb via a back-of-the-hand supporter B12 mounted on the back of the hand from the wrist. 
     It is noted that, in the present modified example, the term “expand” refers to the revolution of the wrist frame  90   b  (the second arm member  6 ) (or the relative revolution of the forearm frame  90   a  (the first arm member  5 ) and the wrist frame  90   b  (the second arm member  6 )) to the direction so that the angle between the forearm frame  90   a  and the wrist frame  90   b  (the angle of the inside of the body) increases. In contrast, the term “bend” refers to the revolution of the wrist frame  90   b  (the second arm member  6 ) (or the relative revolution of the forearm frame  90   a  (the first arm member  5 ) and the wrist frame  90   b  (the second arm member  6 )) to the direction so that the above-described angle decreases. 
     The first arm member  5  of the movement assist device  1  is connected to the forearm of the left arm A2 of the equipped person M via the forearm frame  90   a  of the wrist joint equipment  90 . The second arm member  6  is connected to the hand of the left arm A2 via the wrist frame  90   b . Also in the present modified example, the motor  4 , the first arm member  5 , and the second arm member  6  of the movement assist device  1  are configured to be attachable to and removable from the existing wrist joint equipment  90  by the connection structure similar to the above-described embodiment. 
     Other configuration of the present modified example is basically similar to the above-described embodiment. That is, in response to the trigger that the signal acceptor  53  accepts the first trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  expand. In response to the trigger that the signal acceptor  53  accepts the second trigger signal, the driving controller  61  drives the motor  4  so that the two arm members  5  and  6  bend. It is noted that, in the present modified example, the “switch mode” or the “voice mode” is selected, but the “sensor mode” is not selected. 
     Therefore, the assist according to the physical function of the equipped person can be achieved and thus the advantages similar to the above-described embodiments can be obtained. 
     Further, other than the above-described examples, the approaches of the above-described embodiment and respective modified examples may be utilized in a proper combination thereof. 
     In addition, although not exemplified in detail here, the above-described embodiment and respective modified examples may be implemented with various modifications added within the scope not departing from their spirit. 
     Further, the movement assist device of the present embodiment may be the following first to tenth movement assist devices. The first movement assist device is a movement assist device for assisting physical movement of an equipped person and has a motor including a stator and a rotator, two arm members connected to each of the stator and the rotator and configured to be connected to a predetermined part of a body of the equipped person, a signal acceptor configured to accept a trigger signal that triggers a driving of the motor, and a driving controller configured to drive the motor in a direction so that the two arm members expand in response to a trigger that the signal acceptor accepts a first one of the trigger signal. 
     In the second movement assist device in the first movement assist device, the driving controller is configured to drive the motor in a direction so that the two arm members bend in response to a trigger that the signal acceptor accepts second one of the trigger signal. 
     In the third movement assist device in the first or second movement assist device, the motor and the two arm members are configured to be attachable to and removable from equipment used by the equipped person. 
     In the third movement assist device, the fourth movement assist device has switches configured to output the first trigger signal and the second trigger signal according to a manual operation. 
     In the third or fourth movement assist device, the fifth movement assist device has a voice input unit configured to output the first trigger signal and the second trigger signal according to an inputted voice. 
     In any one of the third to fifth movement assist devices, the sixth movement assist device has a sensor configured to detect a force applied to a sole of the equipped person and output the first trigger signal and the second trigger signal according to the detection result. 
     In the seventh movement assist device in the sixth movement assist device, the sensors are arranged to both legs of the equipped person, the movement assist device further has a driving stopper configured to stop the driving of the motor in response to a trigger that the signal acceptor accepts the first trigger signals from both of the two sensors. 
     In the seventh movement assist device, the eighth movement assist device has a condition setter configured to set a condition under which the driving stopper stops the driving of the motor. 
     In any one of the third to eighth movement assist devices, the ninth movement assist device has a first connector configured to fix one of the two arm members to a corresponding part of the equipment and a second connector configured to connect the other of the two arm members to a corresponding part of the equipment so that they are slidable with respect to any one of the arm members and the equipment in a longitudinal direction. 
     In any one of the second to ninth movement assist devices, the tenth movement assist device has switches configured to output the first trigger signal and the second trigger signal according to a manual operation, a voice input unit configured to output the first trigger signal and the second trigger signal according to the inputted voice, a sensor configured to detect a force applied to a sole of the equipped person and output the first trigger signal and the second trigger signal according to the detection result, and a mode selector configured to select any one of a switch mode in which the trigger signal by the switches is used, a voice mode in which the trigger signal by the voice is used, and a sensor mode in which the trigger signal by the sensor is used. 
     The foregoing detailed description has been presented for the purposes of illustration and description. Many modifications and variations are possible in light of the above teaching. It is not intended to be exhaustive or to limit the subject matter described herein to the precise form disclosed. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims appended hereto.