JP6890286B2 - Standing motion support device, standing motion support method and program - Google Patents

Description

The present disclosure relates to a standing motion support device and the like that support a user's standing motion.

Conventionally, there has been provided a standing motion support device (leg assisting device) that is attached to a user's lower limbs and drives an actuator placed on the user's knees or hips to support the user's standing motion (leg assist device). For example, see Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-2503048

However, the standing motion support device of Patent Document 1 has a problem that it cannot appropriately support the standing motion of the user.

Therefore, the present disclosure provides a standing motion support device capable of appropriately supporting a user's standing motion.

The standing motion support device according to one aspect of the present disclosure includes a first sensor that measures the myoelectric value of the lower leg of the user, a second sensor that measures the knee joint angle of the user, and the front of the trunk of the user. With a third sensor for measuring the tilt angle, at least the first condition that the measured myoelectric value is equal to or greater than the first threshold, and the measured knee joint angle is equal to or less than the second threshold. Based on the second condition and the third condition in which the measured forward tilt angle of the trunk is equal to or greater than the third threshold value, the support start of the standing motion, which is the motion in which the user stands up from the sitting state, is started. A processor that determines whether or not it is possible and outputs an instruction signal when it is determined to be possible, and a support mechanism that starts support for the user's standing operation when the instruction signal is output from the processor. The forward tilt angle of the trunk is an angle between the vertical direction and the trunk of the user, and is an angle that increases as the trunk falls forward of the user .

It should be noted that these comprehensive or specific embodiments may be realized in a recording medium such as a system, method, integrated circuit, computer program or computer readable CD-ROM, system, method, integrated circuit, computer program. And any combination of recording media may be realized.

The standing motion support device of the present disclosure can appropriately support the standing motion of the user.

FIG. 1A is a schematic functional block diagram of the standing motion support device according to the first embodiment. FIG. 1B is a schematic flowchart of the standing motion support method according to the first embodiment. FIG. 2 is a specific functional block diagram of the standing motion support device according to the first embodiment. FIG. 3 is a diagram showing an example of a myoelectric sensor included in the myoelectric measurement unit according to the first embodiment. FIG. 4 is a diagram showing an example of each waveform of the measured voltage output from the amplifier, the rectified voltage output from the rectifier circuit, and the filter processing voltage output from the filter circuit according to the first embodiment. FIG. 5A is a diagram showing an example of the trunk forward tilt angle of the upper body of the user according to the first embodiment. FIG. 5B is a diagram showing an example of a state in which the trunk angle measuring unit is attached to the user according to the first embodiment. FIG. 6 is a diagram showing an angular velocity and a trunk forward tilt angle measured by the trunk angle measuring unit when the user performs a standing motion according to the first embodiment. FIG. 7 is a diagram showing an example of a specific configuration of the support mechanism according to the first embodiment. FIG. 8 is a diagram showing an example of information stored in the storage unit according to the first embodiment. FIG. 9A is a diagram showing another example of information stored in the storage unit according to the first embodiment. FIG. 9B is a diagram showing another example of information stored in the storage unit according to the first embodiment. FIG. 10A is a diagram showing an example of the waveform of the myoelectric value of the tibialis anterior muscle and the first threshold value according to the first embodiment. FIG. 10B is a diagram showing an example of a waveform of the trunk forward tilt angle and a third threshold value according to the first embodiment. FIG. 11A is a diagram showing a flowchart of processing of the standing operation support device according to the first embodiment. FIG. 11B is a more detailed flow chart of the process of step S130 of FIG. 11A. FIG. 12A is a schematic functional block diagram of the standing motion support device according to the second embodiment. FIG. 12B is a diagram showing a schematic flowchart of the standing motion support method according to the second embodiment. FIG. 13 is a functional block diagram of the standing motion support device according to the first modification of the second embodiment. FIG. 14 is a diagram showing an example of the arrangement of the knee angle measuring unit and the knee joint angle according to the first modification of the second embodiment. FIG. 15A is a diagram showing an example in which the user loses balance when the support for the standing motion is started. FIG. 15B is a diagram showing an example of failure of the standing operation. FIG. 16 is a diagram showing the situation of the experiment. FIG. 17 is a diagram showing an example of the measurement result of the amount of muscle activity in the standing motion when the knee joint angles immediately before the standing motion are 65 degrees and 95 degrees. FIG. 18 is a diagram showing the maximum value of the muscle activity of the tibialis anterior muscle when the standing motion is performed at each of the plurality of knee joint angles. FIG. 19 is a diagram showing an example of changing the first threshold value by the determination unit according to the first modification of the second embodiment. FIG. 20 is a flowchart of processing of the standing motion support device according to the first modification of the second embodiment. FIG. 21 is a diagram showing an example of detailed processing in step S132 according to the first modification of the second embodiment. FIG. 22 is a diagram showing another example of the detailed processing of step S132 according to the first modification of the second embodiment. FIG. 23 is a flowchart showing a more detailed process of step S130 of FIG. FIG. 24 is a functional block diagram of the standing motion support device according to the second modification of the second embodiment. FIG. 25 is a diagram showing an example in which the user loses the balance when the support for the standing motion is performed. FIG. 26 is a diagram showing an example of changes in the knee joint angle and the trunk thigh angle when the standing motion is supported. FIG. 27 is a flowchart of processing of the standing motion support device according to the second modification of the second embodiment. FIG. 28 is a flowchart of the more detailed process of step S180 of FIG. 27.

(Knowledge on which this disclosure was based)
The present inventor has found that the following problems occur with respect to the standing operation support device of Patent Document 1 described in the column of "Background technology".

In the standing motion support device attached to the lower limbs of the user as in Patent Document 1, care must be taken so that the user does not lose balance and fall when supporting the standing motion. The main cause of the imbalance is that the user does not correctly perform the posture before standing up, which is assumed by the standing up motion support device. Therefore, the standing motion support device needs to recognize the posture of the user and determine whether the user can stand up without falling before starting the support. Therefore, the standing motion support device of Patent Document 1 measures the horizontal relative position of each foot with respect to the waist position of the user before starting the support. Then, the standing motion support device starts supporting the standing motion of the user when the relative position is within a predetermined range and each foot of the user is in contact with the ground.

The standing motion support device of Patent Document 1 determines whether or not each foot of the user is grounded by a grounding sensor. However, in order to support the standing motion, even if each foot of the user is in contact with the ground, the user needs to exert force on the leg to give strong rigidity to the lower leg. If the user's feet are in contact with the ground but the lower leg does not have strong rigidity, the user can be made to stand even if the user's knees are extended by the standing motion support device starting to support the standing motion. Instead, the lower leg will be moved forward. Further, even if the lower leg has strong rigidity, it becomes difficult for the user to stand up if the user's knee is not properly bent.

In order to solve such a problem, the standing motion support device according to one aspect of the present disclosure includes a first sensor for measuring the myoelectric value of the lower leg of the user and a second sensor for measuring the knee joint angle of the user. Based on the sensor of the above and at least the measured myoelectric value and the knee joint angle, it is determined whether or not it is possible to start the support of the standing motion, which is the motion of the user standing from the sitting state, and it is possible. It includes a processor that outputs an instruction signal when a determination is made, and a support mechanism that starts support for the user's standing operation when the instruction signal is output from the processor. For example, the support mechanism supports the standing motion by supporting the extension of the user's knees. Specifically, the processor has a first condition in which the measured myoelectric value is equal to or higher than the first threshold value, and a second condition in which the measured knee joint angle is equal to or lower than the second threshold value. When both are satisfied, it is determined that the support for the standing operation of the user can be started.

As a result, it is determined whether or not it is possible to start supporting the standing motion of the user based on the myoelectric value of the user's lower leg and the knee joint angle. Therefore, the user's lower leg has strong rigidity and the user can kneel. When properly bent, support for standing movements can be initiated. Therefore, it is possible to suppress the occurrence of failure of the standing operation and appropriately support the standing operation of the user, and it is possible to stand the user in a stable state.

Further, the first sensor may measure the myoelectric value of the tibialis anterior muscle as the myoelectric value of the lower leg.

As a result, the support for the standing motion can be started more appropriately at the timing when the lower leg of the user has strong rigidity, and the user can stand up in a more stable state.

Further, the second threshold value may be 60 ° or more and 100 ° or less.

Thereby, when the user bends his / her knees appropriately, that is, when the user is in a state where he / she can easily stand up, the support for the standing motion can be started. As a result, it is possible to further suppress the occurrence of failure of the standing operation.

Further, the knee joint angle of the user measured by the second sensor may be the smaller angle of the knee joint angle of the left leg and the knee joint angle of the right leg of the user.

As a result, it is determined whether or not the support for the standing motion can be started based on the knee joint angle of the leg of the left leg and the right leg of the user to which the force is applied during the standing motion, so that the user is more stable. It can be stood up in the state of being.

In addition, the standing motion support device further includes a third sensor that measures the trunk anteversion angle of the user, and the processor uses the measured myoelectric value, knee joint angle, and trunk anteversion angle. Based on the above, it may be determined whether or not the support start of the standing motion can be started. Here, for example, the trunk forward tilt angle is an angle between the vertical direction and the user's trunk, and is an angle that increases as the trunk falls forward of the user.

Here, in order for the user to stand up, it is necessary to tilt the upper body (that is, the trunk) forward. If the user's upper body is not tilted sufficiently forward and the support for the standing motion is started, there is a risk that the user will fall backward. However, the standing motion support device of Patent Document 1 starts supporting the standing motion without considering the posture of the upper body of the user. Therefore, the above-mentioned danger may occur.

However, in the standing motion support device according to one aspect of the present disclosure, as described above, the support start of the standing motion of the user is started based on the myoelectric value of the lower leg of the user, the knee joint angle, and the forward tilt angle of the trunk. Is determined whether or not is possible. As a result, it is possible to start supporting the standing motion when the user is tilting the upper body forward. Therefore, it is possible to suppress the occurrence of a fall of the user and more appropriately support the standing operation of the user, and it is possible to stand the user in a more stable state.

Further, the processor measures the first condition in which the measured myoelectric value is equal to or higher than the first threshold value and the second condition in which the measured knee joint angle is equal to or lower than the second threshold value. When both the third condition that the trunk forward tilt angle is equal to or higher than the third threshold value is satisfied, it may be determined that the support for the standing motion of the user can be started.

As a result, when the knee joint angle is large and the trunk anteversion angle is small, the support for the user's standing motion is not started, and when the knee joint angle is small and the trunk anteversion angle is large, the user Support for the standing motion of is started. Therefore, when the user extends the leg forward and increases the knee joint angle, the support for the standing motion is started, so that the risk that the user loses balance and falls can be suppressed. it can. Further, when the user does not tilt his / her upper body forward, the support for the standing motion is started, so that the risk of the user falling backward can be suppressed.

Further, the processor further sets the first threshold value so that the smaller the measured knee joint angle, the smaller the first threshold value, and the measured myoelectric value is the first threshold value. When both the first condition described above and the third condition in which the measured forward tilt angle of the trunk is equal to or greater than the third threshold value are satisfied, it is possible to start supporting the standing motion of the user. It may be determined that.

As a result, when the knee joint angle is large, the support for the user's standing motion is not started unless the user's lower leg has stronger rigidity, and when the knee joint angle is small, the rigidity of the user's lower leg is weak. Also, support for the user's standing motion is started. Therefore, when the user extends the leg forward to increase the knee joint angle, the support for the standing motion is started even though the rigidity of the user's lower leg is not sufficiently strong, so that the user balances. It is possible to suppress the risk of collapsing and falling.

Further, the processor further outputs a notification signal for urging the user to bend the knee when the measured myoelectric value and the trunk forward tilt angle are changed periodically. May be good.

When the myoelectric value of the lower leg and the forward tilt angle of the trunk are changing periodically, the user is trying to stand up, but cannot stand up because of the large knee joint angle. The situation is repeating the act. In such a situation, a notification signal for urging the user to bend the knee is output. This notification signal presents, for example, a voice or character prompting the user to bend the knee. The presentation causes the user to bend his knees. When the knee is bent, that is, when the knee joint angle is reduced, the first threshold value is set small, so that the first condition is easily satisfied. As a result, it is determined that the support for the standing motion can be started, and the user can receive the support for the standing motion by the support mechanism and can easily stand up.

Further, the standing motion support device further includes a fourth sensor for measuring the trunk thigh angle, which is an angle between the user's trunk and thigh, and the processor is measured during the standing motion. The first threshold value may be changed based on the respective changes in the knee joint angle and the trunk thigh angle. For example, the processor may change the first threshold value to a larger value when the rate of change of the trunk thigh angle measured during the standing motion is larger than the rate of change of the knee joint angle. ..

When the rate of change of the trunk thigh angle measured during the standing motion is larger than the rate of change of the knee joint angle, it is assumed that the user is in an unstable state during the standing motion. Therefore, in such a case, by changing the first threshold value to a larger value, the next time the user performs the standing operation, the standing operation is performed at the timing determined by using the changed first threshold value. Support is started. Therefore, the timing at which the support for the standing motion is started can be delayed, and as a result, the user can stand up in a more stable state.

Further, the standing motion support device according to one aspect of the present disclosure is measured at least by a first sensor that measures the myoelectric value of the user's lower leg and a second sensor that measures the knee joint angle of the user. Based on the myoelectric value and the knee joint angle, it is determined whether or not the support for the standing motion, which is the motion of the user to stand up from the sitting state, can be started. It may be provided with a processor that outputs an instruction signal to a support mechanism that supports the above.

As a result, similarly to the above, it is possible to appropriately support the standing operation of the user, and it is possible to stand the user in a stable state.

Hereinafter, embodiments will be specifically described with reference to the drawings.

It should be noted that all of the embodiments described below show comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, step order, and the like shown in the following embodiments are examples, and are not intended to limit the present disclosure. Further, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept are described as arbitrary components.

Further, each figure is a schematic view and is not necessarily exactly illustrated. Further, in each figure, the same components are designated by the same reference numerals.

(Embodiment 1)
[Overview]
FIG. 1A shows a schematic functional block diagram of the standing motion support device according to the present embodiment. As shown in FIG. 1, the standing operation support device 10 includes a first sensor 11, a third sensor 12a, a processor 15, and a support mechanism 17.

The first sensor 11 measures the myoelectric value of the user's lower leg. The third sensor 12a measures the trunk forward tilt angle of the user. Based on the measured myoelectric value and the forward tilt angle of the trunk, the processor 15 determines whether or not it is possible to start supporting the standing motion, which is the motion in which the user stands up from the sitting state, and determines that it is possible. If so, an instruction signal is output. When the instruction signal is output from the processor 15, the support mechanism 17 starts to support the user's standing operation. The standing motion support device 10 according to the present embodiment includes the support mechanism 17, but does not have to include the support mechanism 17.

FIG. 1B shows a schematic flowchart of the standing motion support method according to the present embodiment. In this standing motion support method, first, the first sensor 11 measures the myoelectric value of the user's lower leg (step S11). Next, the third sensor 12a measures the trunk forward tilt angle of the user (step S12a). Next, the processor 15 determines whether or not it is possible to start supporting the standing motion, which is the motion of standing up from the sitting state of the user, based on the measured myoelectric value and the trunk forward tilt angle (). Step S13). Here, when it is determined that the processor 15 is possible (YES in step S13), the support mechanism 17 starts supporting the standing operation of the user (step S14).

As a result, it is determined whether or not it is possible to start supporting the standing motion of the user based on the myoelectric value of the user's lower leg and the forward tilt angle of the trunk. When the upper body is tilted forward, support for standing up can be started. Therefore, it is possible to appropriately support the user's standing operation by suppressing the occurrence of the user's fall or failure of the standing operation, and it is possible to stand the user in a stable state.

Hereinafter, details of such a standing motion support device and a standing motion support method will be described.

[Device configuration]
FIG. 2 shows a specific functional block diagram of the standing motion support device according to the present embodiment. As shown in FIG. 2, the standing motion support device 100 includes a myoelectric measurement unit 101, a trunk angle measurement unit 102, a timer 103, a measurement processing unit 109, a storage unit 104, a determination unit 105, a support request unit 106, and support. The mechanism 107 is provided. The standing motion support device 100 shown in FIG. 2 is a device that embodies the standing motion support device 10 shown in FIG. 1A. Further, the myoelectric measurement unit 101, the trunk angle measurement unit 102, and the determination unit 105 shown in FIG. 2 correspond to the first sensor 11, the third sensor 12a, and the processor 15 shown in FIG. 1A, respectively. Further, the support mechanism 107 shown in FIG. 2 corresponds to the support mechanism 17 shown in FIG. 1A.

[Muscle electrical measurement unit 101]
The myoelectric measurement unit 101 measures the myoelectric value of the tibialis anterior muscle as the myoelectric value of the lower leg described above. That is, the myoelectric measurement unit 101 measures the myoelectric value of the user's tibialis anterior muscle using electrodes arranged on the user's lower limbs (specifically, the lower leg). Here, the myoelectric value may be a measured value directly obtained from the electrode, or may be a value calculated or processed from the measured value. The myoelectric measurement unit 101 measures the myoelectric value of the tibialis anterior muscles of both legs of the user.

FIG. 3 shows an example of the myoelectric sensor included in the myoelectric measurement unit 101. The myoelectric measurement unit 101 includes, for example, two myoelectric sensors 1011. One myoelectric sensor 1011 measures the myoelectric value of the tibialis anterior muscle of the user's right leg, and the other myoelectric sensor 1011 is on the left side of the user. Measure the myoelectric value of the tibialis anterior muscle of the leg.

As shown in FIG. 3, the myoelectric sensor 1011 has, for example, two electrodes 1012a and 1012b, an amplifier 1014, a rectifier circuit 1013, and a filter circuit 1015.

Electrodes 1012a and 1012b are placed on the skin just above the user's tibialis anterior muscle. The tibialis anterior muscle is a muscle located in the superficial lateral layer of the anterior surface of the lower leg. For example, the distance between the electrode 1012a and the electrode 1012b is about 10 to 30 mm.

The amplifier 1014 is, for example, a differential amplifier circuit. The amplifier 1014 amplifies the difference voltage between the potential V1 measured using the electrode 1012a and the potential V2 measured using the electrode 1012b, and outputs the amplified difference voltage as the measurement voltage. The potential V1 is the potential difference between the ground and the electrode 1012a, and the potential V2 is the potential difference between the ground and the electrode 1012b.

The rectifier circuit 1013 outputs the full-wave rectified measured voltage as a rectified voltage by performing full-wave rectification with respect to the measured voltage output from the amplifier 1014. The filter circuit 1015 performs a low-frequency pass filter (that is, a low-pass filter) process on the rectified voltage, and outputs the low-frequency pass-filtered rectified voltage as a filter-processed voltage.

The myoelectric measurement unit 101 measures the average value, the maximum value, or the minimum value of the filtering voltage output from each of the two myoelectric sensors 1011 as the myoelectric value of the tibialis anterior muscle.

FIG. 4 shows an example of the waveforms of the measured voltage output from the amplifier 1014, the rectified voltage output from the rectifier circuit 1013, and the filter processing voltage output from the filter circuit 1015. In FIG. 4, the vertical axis represents voltage (μV) and the horizontal axis represents time (sec).

The amplifier 1014 outputs a measured voltage having a waveform as shown in FIG. 4A. As shown in FIG. 4B, the rectifier circuit 1013 performs full-wave rectification on the measured voltage of the waveform shown in FIG. 4A. Next, as shown in FIG. 4C, the filter circuit 1015 is lower than the full-wave rectified waveform shown in FIG. 4B in order to obtain an envelope of the full-wave rectified waveform. Performs regional frequency passage filtering.

The frequency band passed by the low-pass filter processing is, for example, a band of 2 Hz or less. By this process, the frequency component larger than 2 Hz contained in the rectified voltage is attenuated. The waveform of the rectified voltage subjected to such low-pass filtering is also referred to as the activity waveform of the tibialis anterior muscle. The value at each time included in the activity waveform of the tibialis anterior muscle is also referred to as the activity value of the tibialis anterior muscle at that time.

Further, the myoelectric value measured by the myoelectric measuring unit 101 may be a measured value directly obtained from the electrodes 1012a and 1012b as described above, or may be a value corresponding to the measured value. The value corresponding to the measured value is a value obtained by performing processing such as amplification, full-wave rectification, or low-pass filter processing on the directly obtained measured value.

[Torso angle measuring unit 102]
The trunk angle measuring unit 102 measures the trunk forward tilt angle of the user's upper body.

FIG. 5A shows an example of the trunk forward tilt angle of the upper body of the user. As shown in FIG. 5A, the trunk forward tilt angle is the angle 601 of the user's trunk with respect to the vertical direction. That is, the trunk forward tilt angle is an angle between the vertical direction and the user's trunk, and is an angle that increases as the trunk falls forward of the user. The trunk of the user is, for example, the spine of the user.

An example of specific hardware of the trunk angle measuring unit 102 is a 9-axis sensor. The 9-axis sensor includes an acceleration sensor, an angular velocity sensor, and a geomagnetic sensor. These acceleration sensor, angular velocity sensor, and geomagnetic sensor have an accelerometer side circuit, an angular velocity measurement circuit, and a geomagnetic measurement circuit, respectively. The angle of the trunk with respect to the vertical direction can be calculated as the trunk forward tilt angle by the 9-axis sensor. When only the angular velocity sensor of the 9-axis sensor is used, the trunk forward tilt angle can be calculated by performing calibration and integrating the measured values of the angular velocity sensor.

FIG. 5B shows an example of a state in which the trunk angle measuring unit 102 is attached to the user. The trunk angle measuring unit 102 is arranged on the waist of the user sitting on the chair 603. Further, as shown in FIG. 5B, the x-axis, y-axis and z-axis of the sensor are set. The x-axis is, for example, an axis along the vertical direction, and upward is a positive direction. The y-axis direction is, for example, an axis perpendicular to the x-axis and along the left-right direction of the user, and the left direction is a positive direction. The z-axis direction is, for example, an axis perpendicular to the x-axis and along the front-back direction of the user, and the rearward direction is a positive direction. The accelerometer measures the acceleration of each of the trunk angle measuring units 102 in the x-axis direction, the y-axis direction, and the z-axis direction. The geomagnetic sensor measures the geomagnetic intensities in the x-axis direction, the y-axis direction, and the z-axis direction, respectively. The angular velocity sensor measures the angular velocity at which the trunk angle measuring unit 102 rotates with each of the x-axis, y-axis, and z-axis as the center of rotation.

FIG. 6 shows the angular velocity with the y-axis as the center of rotation and the trunk forward tilt angle measured by the trunk angle measuring unit 102 when the user performs the standing motion. The solid line in the graph of FIG. 6 shows the angular velocity 604 centered on the y-axis when the user makes a forward bending motion during the standing motion, which is measured by the angular velocity sensor of the trunk angle measuring unit 102. The dotted line in the graph of FIG. 6 indicates the trunk forward tilt angle 605 obtained by integrating the measured angular velocities 604. As shown in FIG. 6, the trunk forward tilt angle 605 increases as the user bends forward, and decreases as the user returns to the original posture after bending forward.

The angular velocity sensor directly measures the amount of change in the angular velocity, and measures the angular velocity by integrating the amount of change with the angular velocity measurement circuit. The trunk angle measuring unit 102 measures the trunk forward tilt angle as a value obtained by adding the cumulative value of the angular velocity measured by the angular velocity sensor to the initial angle. The initial angle may be set by calibration, or may be stored in advance in the internal memory of the trunk angle measuring unit 102. Further, the trunk angle measuring unit 102 may correct the initial angle held in advance by calibration. For example, the standing motion support device 100 instructs the user to arrange the trunk angle measuring unit 102 along the x-axis direction (vertical direction), and the trunk measured by the trunk angle measuring unit 102 after the instruction. The forward tilt angle is set to the initial angle (that is, 0 deg).

Further, the trunk forward tilt angle measured by the trunk angle measuring unit 102 may be an angle calculated from a measured value directly obtained from the 9-axis sensor, and is calculated from a value corresponding to the measured value. It may be an angle. The value corresponding to the measured value is a value obtained by performing processing such as amplification, rectification, or filtering on the directly obtained measured value.

[Support Request Department 106]
The support requesting unit 106 requests the support mechanism 107 to start supporting the standing motion in response to the movement or operation of the user. For example, the support request unit 106 requests the start of support by operating a button, or requests the start of support by operating a voice. Specifically, when the button arranged on the standing motion support device 100 is pressed by the user, the support requesting unit 106 requests the support mechanism 107 to start supporting the standing motion. Alternatively, when the user utters a keyword and the voice recognition circuit arranged in the standing motion support device 100 recognizes the keyword, the support requesting unit 106 requests the start of support for the standing motion.

[Support mechanism 107]
The support mechanism 107 supports the standing motion by supporting the extension of the user's knees. When such a support mechanism 107 receives a request for starting support from the support request unit 106, the support mechanism 107 acquires the current determination result by the determination unit 105. When the determination result indicates that the support can be started, the support mechanism 107 starts the support for the user's standing motion. The determination result indicating that the support can be started is output to the support mechanism 107 from the determination unit 105, which is a processor, as the above-mentioned instruction signal. The assist mechanism 107 starts assisting the user's standing operation when an instruction signal is output from the processor.

Further, as described above, the support mechanism 107 acquires the current determination result by the determination unit 105 when receiving the support start request from the support request unit 106, but even if the current determination result is always acquired. Good. In this case, when the support mechanism 107 receives a request for support start from the support request unit 106 when the current determination result indicates that the support can be started, the support mechanism 107 starts the support for the user's standing operation.

Such a support mechanism 107 is, for example, a robot or an assist suit worn on the lower limbs of the user.

FIG. 7 shows an example of a specific configuration of the support mechanism 107. As shown in FIG. 7, the support mechanism 107 has an upper skeleton 1061, a lower skeleton 1062, and a power unit 1063. The upper skeleton 1061 is rotatably connected to the lower skeleton 1062 via a power unit 1063.

The upper skeleton 1061 is fixed to the thigh of the user's lower limbs. The lower skeleton 1062 is fixed to the foot or lower leg of the user's lower limbs. The upper skeleton 1061 and the lower skeleton 1062 have fixing devices 1065 and 1066, respectively, and are fixed to the user by the fixing devices. Fixtures 1065 and 1066 are, for example, tapes (A hook and loop fasteners) or belts. The fixtures 1065 and 1066 may be string-shaped. The power unit 1063 has, for example, a motor and a power source.

Here, the thigh corresponds to the portion of the leg above the knee. The lower leg corresponds to the part of the leg from the knee to the ankle.

As shown in FIG. 7, the power unit 1063 arranges the upper skeleton 1061 in the direction in which the user's knee is extended (direction of arrow 1064) with the center between the upper skeleton 1061 and the lower skeleton 1062 (or the user's knee). move. As a result, it is possible to support the user's standing operation.

In the case of a cloth-like assist suit in which the support mechanism 107 is worn by the user, the upper skeleton 1061 and the lower skeleton 1062 may be included in the cloth, respectively.

[Timer 103]
The timer 103 measures the current time and outputs a time signal indicating the time measured to the measurement processing unit 109. For example, the timer 103 outputs a time signal indicating the current time every 0.01 seconds.

[Storage 104]
The storage unit 104 is a storage medium having a storage area for storing the myoelectric value of the tibialis anterior muscle and the forward tilt angle of the trunk, and is composed of, for example, a hard disk or a memory.

[Measurement processing unit 109]
The measurement processing unit 109 includes the time indicated by the time signal output from the timer 103, the myoelectric value of the tibialis anterior muscle measured by the myoelectric measurement unit 101 at that time, and the trunk angle measurement unit 102 at that time. To obtain the trunk forward tilt angle measured by. Then, the measurement processing unit 109 stores the time, the myoelectric value, and the trunk forward tilt angle in the storage unit 104 in association with each other.

FIG. 8 shows an example of the information stored in the storage unit 104.

The measurement processing unit 109 has the time "13: 45: 30.00" indicated by the time signal, the myoelectric value "0.000639V" of the tibialis anterior muscle at that time, and the trunk anteversion angle "18" at that time. It is stored in the storage unit 104 in association with ".32 deg". Further, the measurement processing unit 109 may store the time, the myoelectric value, and the trunk forward tilt angle in the storage unit 104 in association with each other, for example, every 0.01 seconds. Further, the measurement processing unit 109 may acquire the user ID, which is the identification information of the user, and store the user ID in the storage unit 104 in association with the time, the myoelectric value, and the trunk forward tilt angle. Further, when the myoelectric value of the vastus medialis muscle is measured, the measurement processing unit 109 also associates the myoelectric value of the vastus medialis muscle with the time when the myoelectric value is measured and stores the storage unit 104. It may be stored in.

9A and 9B show other examples of information stored in the storage unit 104.

The timer 103 may output a clock signal instead of outputting the time signal as described above. In this case, the measurement processing unit 109 calculates the time at the time of each passage of the first time interval (for example, 0.001 second) based on the clock signal, and the tibialis anterior muscle measured at that time. The myoelectric value is acquired from the myoelectric measurement unit 101. Then, as shown in FIG. 9A, the measurement processing unit 109 associates the acquisition order in which the myoelectric values are acquired with the myoelectric values and the time calculated when the myoelectric values are acquired. Is stored in the storage unit 104. For example, the measurement processing unit 109 stores the acquisition order “1”, the first acquired myoelectric value, and the reference time (for example, 0 sec) in association with each other. Further, the measurement processing unit 109 stores the acquisition order “2”, the second acquired myoelectric value, and the time “reference time + first time interval” (sec) in association with each other. Further, the measurement processing unit 109 stores the acquisition order “3”, the third acquired myoelectric value, and the time “reference time + first time interval × 2” (sec) in association with each other. In this way, the measurement processing unit 109 sets the acquisition order "n", the nth acquired myoelectric value, and the time "reference time + first time interval x (n-1)" (sec). Store in association with each other (n is a natural number).

Similarly, the measurement processing unit 109 calculates the time at the time of each passage of the second time interval (for example, 0.01 second) based on the clock signal, and the trunk forward tilt angle measured at that time. Is obtained from the trunk angle measuring unit 102. Then, as shown in FIG. 9B, the measurement processing unit 109 calculates when the acquisition order in which the trunk forward tilt angle is acquired, the trunk forward tilt angle, and the trunk forward tilt angle are acquired. It is stored in the storage unit 104 in association with the time. For example, the measurement processing unit 109 stores the acquisition order “1”, the first acquired trunk forward tilt angle, and the reference time (for example, 0 sec) in association with each other. Further, the measurement processing unit 109 stores the acquisition order “2”, the second acquired trunk forward tilt angle, and the time “reference time + second time interval” (sec) in association with each other. Further, the measurement processing unit 109 stores the acquisition order “3”, the third acquired trunk forward tilt angle, and the time “reference time + second time interval × 2” (sec) in association with each other. To do. In this way, the measurement processing unit 109 has the acquisition order “n”, the nth acquired trunk forward tilt angle, and the time “reference time + second time interval × (n-1)” (sec). Is stored in association with (n is a natural number). The first time interval and the second time interval may be different, but it is desirable that they are the same.

[Determination unit 105]
The determination unit 105 determines whether or not the user's state may start supporting the standing motion based on the myoelectric value of the user's tibialis anterior muscle and the trunk forward tilt angle of the user's upper body. .. In other words, the determination unit 105 determines whether or not it is possible to start supporting the user's standing motion by using both the myoelectric value of the user's tibialis anterior muscle and the user's trunk anteversion angle. More specifically, the determination unit 105 has a first condition in which the measured myoelectric value is equal to or greater than the first threshold value, and a third condition in which the measured trunk anteversion angle is equal to or greater than the third threshold value. When both the conditions are satisfied, it is determined that the support for the user's standing motion can be started. In other words, the determination unit 105 determines when (i) the myoelectric value of the user's tibialis anterior muscle is equal to or greater than the first threshold value and (ii) the trunk anteversion angle of the user's upper body is equal to or greater than the third threshold value. It is judged that it is possible to start supporting the standing motion of. The determination unit 105 may store the first threshold value and the third threshold value in advance, or may read the first threshold value and the third threshold value from an external recording medium.

Here, the myoelectric value and the trunk forward tilt angle used for the determination are, for example, the myoelectric value and the trunk forward tilt angle associated with the latest time stored in the storage unit 104. That is, each time the determination unit 105 stores the myoelectric value and the trunk forward tilt angle associated with the latest time in the storage unit 104, the determination unit 105 refers to the storage unit 104 to obtain the latest myoelectric value. And identify the trunk forward tilt angle. Then, the determination unit 105 determines whether or not the above-mentioned support start is possible at the present time, based on the specified myoelectric value and the trunk forward tilt angle.

FIG. 10A shows an example of the waveform of the myoelectric value of the tibialis anterior muscle and the first threshold value, and FIG. 10B shows an example of the waveform of the trunk anteversion angle and the third threshold value.

As shown in FIG. 10A, the determination unit 105 determines whether or not the myoelectric value of the user's tibialis anterior muscle is equal to or higher than the first threshold value (for example, 200 μV). Further, as shown in FIG. 10B, the determination unit 105 determines whether or not the forward tilt angle of the user's trunk is equal to or greater than a third threshold value (for example, 23 deg). Then, the determination unit 105 determines that the support for the user's standing motion can be started when the myoelectric value is equal to or higher than the first threshold value and the trunk forward tilt angle is equal to or higher than the third threshold value. At this time, the determination unit 105 outputs the above-mentioned instruction signal to the support mechanism 107.

The determination unit 105 can obtain the myoelectric value of the user's tibialis anterior muscle and the user's body from the myoelectric measurement unit 101 and the trunk angle measurement unit 102 without referring to the information stored in the storage unit 104. The trunk forward tilt angle may be obtained directly. At this time, the determination unit 105 may acquire the time when the myoelectric value and the trunk forward tilt angle are measured from the myoelectric measurement unit 101 and the trunk angle measurement unit 102. Alternatively, the determination unit 105 may store the first time interval and the second time interval in the internal memory. In this case, the determination unit 105 uses the first time interval and the second time interval to acquire the myoelectric value of the tibialis anterior muscle of the user and the trunk anteversion angle of the upper body of the user. Is calculated. Then, the determination unit 105 acquires the myoelectric value and the trunk forward tilt angle at the calculated time based on the clock signal from the timer 103, and the latest acquired myoelectric value and the trunk forward tilt angle. Based on the above, it may be determined whether or not the above-mentioned support start is possible at this time.

[Processing of the standing motion support device 100]
FIG. 11A shows a flowchart of processing of the standing operation support device 100.

(Step S110)
The myoelectric measurement unit 101 measures the myoelectric value of the user's tibialis anterior muscle. The measured myoelectric value is a value (for example, an average value, a minimum value, a maximum value, etc.) obtained from the myoelectric value of the tibialis anterior muscles of both legs of the user.

(Step S120)
The trunk angle measuring unit 102 measures the user's trunk forward tilt angle.

(Step S130)
The determination unit 105 determines whether or not the support for the standing motion can be started based on the myoelectric value of the tibialis anterior muscle measured in step S110 and the trunk anteversion angle measured in step S120. When the determination unit 105 determines that the support for the standing motion can be started, the standing motion support device 100 proceeds to the process of step S140. On the other hand, when the determination unit 105 determines that it is impossible to start the support for the standing motion, the standing motion support device 100 returns to the processes of steps S110 and S120.

(Step S140)
The support mechanism 107 confirms whether or not there is a request from the support request unit 106 to start the support for the standing motion. When there is a request to start support, the standing operation support device 100 proceeds to the process of step S150. If there is no request to start support, the standing operation support device 100 returns to the processing of steps S110 and S120.

(Step S150)
The support mechanism 107 starts supporting the user's standing motion.

[Details of processing of determination unit 105]
FIG. 11B shows a more detailed flow chart of the process of step S130 of FIG. 11A.

(Step S131)
The determination unit 105 acquires the myoelectric value of the tibialis anterior muscle from the storage unit 104.

(Step S132)
The determination unit 105 determines whether or not the myoelectric value of the tibialis anterior muscle acquired in step S131 is equal to or greater than the first threshold value. Here, the fact that the myoelectric value of the tibialis anterior muscle is equal to or higher than the first threshold value indicates that the tibialis anterior muscle is active.

When it is determined that the myoelectric value of the tibialis anterior muscle is equal to or higher than the first threshold value, the determination unit 105 proceeds to the process of step S133. On the other hand, when it is determined that the myoelectric value of the tibialis anterior muscle is smaller than the first threshold value, the determination unit 105 returns to the process of step S131. Here, after returning to the process of step S131, the determination unit 105 acquires a new myoelectric value of the tibialis anterior muscle.

The determination unit 105 may determine whether or not the tibialis anterior muscle is active by using the amount of change in the myoelectric value of the tibialis anterior muscle instead of the myoelectric value of the tibialis anterior muscle. For example, the determination unit 105 detects that the amount of change in the myoelectric value of the tibialis anterior muscle is equal to or greater than the threshold value, and stores the time when the myoelectric value used at that time is measured in the storage unit 104 as tb. You may. Here, when the amount of change in the myoelectric value (Ib-Ia) of the tibialis anterior muscle is equal to or greater than the threshold value, the time at which the myoelectric value Ib is measured is defined as tb. When the time ta is earlier than the time tb (ta <tb), the myoelectric value measured at the time ta is defined as Ia, and the myoelectric value measured at the time tb is defined as Ib. When the amount of change is equal to or greater than the threshold value, the relationship Ib> Ia holds.

(Step S133)
The determination unit 105 acquires the trunk forward tilt angle from the storage unit 104.

(Step S134)
The determination unit 105 determines whether or not the trunk forward tilt angle acquired in step S133 is equal to or greater than the third threshold value. When it is determined that the trunk forward tilt angle is equal to or greater than the third threshold value, the standing motion support device 100 proceeds to the process of step S140. When it is determined that the trunk forward tilt angle is smaller than the third threshold value, the determination unit 105 returns to the process of step S131. Here, the determination unit 105 returns to the process of step S131, and when the process of step S133 is reached again, newly acquires the myoelectric value and the trunk forward tilt angle. The determination unit 105 may determine whether or not the amount of change is equal to or greater than the threshold value by using the amount of change in the forward tilt angle of the trunk instead of the forward tilt angle of the trunk.

[effect]
As described above, in the present embodiment, it is determined whether or not it is possible to start supporting the standing motion of the user based on the myoelectric value of the user's lower leg and the forward tilt angle of the trunk, so that the user's lower leg is strong. It is rigid and can start assisting in standing movements when the user is leaning forward. Therefore, it is possible to appropriately support the user's standing operation by suppressing the occurrence of the user's fall or failure of the standing operation, and it is possible to stand the user in a stable state.

Further, in the present embodiment, the first condition that the measured myoelectric value is equal to or higher than the first threshold value and the third condition that the measured trunk forward tilt angle is equal to or higher than the third threshold value are satisfied. When both are satisfied, it is determined that the support for the user's standing motion can be started. Therefore, the lower leg of the user has strong rigidity, and the support for the standing motion can be started more appropriately at the timing when the user tilts the upper body forward, and the user can stand up in a more stable state.

(Embodiment 2)
In the standing motion support device according to the first embodiment, the myoelectric value of the lower limbs of the user and the forward tilt angle of the trunk are measured in order to determine whether or not the support for the standing motion can be started. On the other hand, the standing motion support device according to the present embodiment measures the knee joint angle of the user instead of the trunk forward tilt angle. The knee joint angle is also referred to as the knee joint angle.

[Overview]
FIG. 12A shows a schematic functional block diagram of the standing motion support device according to the present embodiment. As shown in FIG. 1, the standing motion support device 10 includes a first sensor 11, a second sensor 12, a processor 15, and a support mechanism 17.

The first sensor 11 measures the myoelectric value of the user's lower leg. The second sensor 12 measures the knee joint angle of the user. Based on the measured myoelectric value and the knee joint angle, the processor 15 determines whether or not it is possible to start supporting the standing motion, which is the motion in which the user stands up from the sitting state, and when it is determined that it is possible. Outputs an instruction signal to. When the instruction signal is output from the processor 15, the support mechanism 17 starts to support the user's standing operation. The standing motion support device 10 according to the present embodiment includes the support mechanism 17, but does not have to include the support mechanism 17.

FIG. 12B shows a schematic flowchart of the standing motion support method according to the present embodiment. In this standing motion support method, first, the first sensor 11 measures the myoelectric value of the user's lower leg (step S11). Next, the second sensor 12 measures the knee joint angle of the user (step S12). Next, based on the measured myoelectric value and the knee joint angle, the processor 15 determines whether or not it is possible to start supporting the standing motion, which is the motion in which the user stands up from the sitting state (step S13). ). Here, when it is determined that the processor 15 is possible (YES in step S13), the support mechanism 17 starts supporting the standing operation of the user (step S14).

As a result, it is determined whether or not it is possible to start supporting the standing motion of the user based on the myoelectric value of the user's lower leg and the knee joint angle. Therefore, the user's lower leg has strong rigidity and the user can kneel. When properly bent, support for standing movements can be initiated. Therefore, it is possible to suppress the occurrence of failure of the standing operation and appropriately support the standing operation of the user, and it is possible to stand the user in a stable state.

For example, as in the first embodiment, the first sensor 11a measures the myoelectric value of the tibialis anterior muscle as the myoelectric value of the lower leg. Then, the support mechanism 17 supports the standing motion by supporting the extension of the user's knee.

Specifically, the processor 15 has both a first condition in which the measured myoelectric value is equal to or higher than the first threshold value and a second condition in which the measured knee joint angle is equal to or lower than the second threshold value. If it is satisfied, it is determined that the support for the user's standing motion can be started. Here, for example, the second threshold value is 60 ° or more and 100 ° or less. The user's knee joint angle measured by the second sensor 12 is the smaller of the user's left leg knee joint angle and the right leg knee joint angle.

(Modification example 1)
Here, the standing motion support device 10 may further include a third sensor 12a for measuring the forward tilt angle of the user's trunk, as in the first embodiment. In this case, the processor 15 determines whether or not the support for the standing motion can be started based on the measured myoelectric value, the knee joint angle, and the trunk forward tilt angle.

In this modification, unlike the first embodiment, the first threshold value of the myoelectric value used for determining whether or not the tibialis anterior muscle is active is changed according to the angle of the knee joint of the user.

[Device configuration]
FIG. 13 shows an example of a functional block diagram of the standing motion support device according to this modified example. The standing motion support device 100A according to this modification includes each component of the standing motion support device 100 shown in FIG. 2, and further includes a knee angle measuring unit 108 for measuring the knee joint angle.

[Knee angle measuring unit 108]
The knee angle measuring unit 108 is a second sensor that measures the knee joint angle of the user, and is composed of, for example, an encoder.

FIG. 14 shows an example of the arrangement of the knee angle measuring unit 108 and the knee joint angle.

For example, as shown in FIG. 14, the knee angle measuring unit 108 composed of an encoder is installed in the power unit 1063 having a motor, and measures the rotation angle of the motor of the power unit 1063. Then, the knee angle measuring unit 108 calculates the knee joint angle θ, which is the angle formed by the upper skeleton 1061 and the lower skeleton 1062, from the rotation angle. As a result, the knee joint angle θ is measured.

FIG. 15A shows an example in which the user loses balance when the support for the standing operation is started, and FIG. 15B shows an example in which the standing operation fails.

For example, as shown in FIG. 15A, when the support for the standing motion is started in a state where the knee joint angle is large, the user may lose the balance and fall. Further, as shown in FIG. 15B, when the support for the standing motion is started in a state where the knee joint angle is large, the user may not be able to stand and may extend the knee while sitting. However, in the standing motion support device 100A according to the present modification, it is determined whether or not the standing motion support can be started by using the knee joint angle measured by the knee angle measuring unit 108. As a result, the risk of the above-mentioned fall can be reduced.

Here, an experiment conducted to derive the relationship between the knee joint angle and the myoelectric value will be described.

FIG. 16 shows the situation of the experiment. In this experiment, as shown in FIG. 16, the amount of muscle activity of the tibialis anterior muscle when the knee joint angle immediately before the standing motion was changed was measured using a myoelectric potential sensor and a motion sensor arranged on the lower limbs. The amount of muscle activity corresponds to the above-mentioned myoelectric value.

FIG. 17 shows an example of the measurement result of the amount of muscle activity in the standing motion when the knee joint angles immediately before the standing motion were 65 degrees and 95 degrees.

As shown in FIGS. 17A and 17B, when the user stands up at a knee joint angle of 65 degrees immediately before the standing up motion, the user stands up at the knee joint angle of 95 degrees, as compared with the case where the user stands up during the standing up motion. The amount of muscle activity is small. More specifically, when the knee joint angle is 65 degrees, the maximum value of muscle activity is about 0.06 V, whereas when the knee joint angle is 95 degrees, the maximum value of muscle activity is about 0.06 V. It is about 0.3V.

FIG. 18 shows the maximum value of the muscle activity of the tibialis anterior muscle when the standing motion is performed at each of the plurality of knee joint angles. As shown in FIG. 18, as the knee joint angle increases, the maximum value of the amount of muscle activity required for the standing motion increases.

This means that if the first threshold value of the myoelectric value is used, the standing motion can be correctly determined at a certain knee joint angle, but cannot be correctly determined at another knee joint angle. Shown. More specifically, in a situation where there is a relationship between the knee joint angle and the amount of muscle activity as shown in FIG. 18, for example, the first threshold value is set to 0.15 V. In such a case, when the standing motion is performed with the knee joint angle smaller than 80 degrees, the myoelectric value does not exceed 0.15V, so that it is not determined that the support for the standing motion can be started. On the other hand, the first threshold value is set to 0.04V. In such a case, if the user increases the knee joint angle, it is determined that the support for the standing motion can be started even if the user does not intend to stand or is not in a standing position. It may end up. As a result, depending on the knee joint angle, the user may fall, which can be dangerous. Therefore, in this modified example, the first threshold value is changed according to the knee joint angle.

The knee joint angle measured by the knee angle measuring unit 108 may be an angle calculated by using a measured value directly obtained from the encoder, and an angle calculated by using a value corresponding to the measured value. It may be. The value corresponding to the measured value is a value obtained by performing processing such as amplification, rectification, or filtering on the directly obtained measured value.

[Determination unit 105]
The determination unit 105 according to this modification changes the first threshold value according to the knee joint angle measured by the knee angle measurement unit 108. That is, the determination unit 105 sets the first threshold value so that the smaller the measured knee joint angle, the smaller the first threshold value. Then, the determination unit 105 has both the first condition that the measured myoelectric value is equal to or higher than the first threshold value and the third condition that the measured trunk forward tilt angle is equal to or higher than the third threshold value. If it is satisfied, it is determined that the support for the user's standing motion can be started.

FIG. 19 shows an example of changing the first threshold value by the determination unit 105.

For example, as shown in FIG. 19, if the measured knee joint angle is larger than the second threshold value θ2 (for example, 90 deg), the determination unit 105 sets the first threshold value to the = 300 μV and measures the knee joint. If the angle is equal to or less than the second threshold value θ2, the first threshold value is set to thb = 160 μV. In this way, the first threshold value is switched between the and thb according to the knee joint angle. The determination unit 105 may store the second threshold value θ2 in advance, or may read the second threshold value θ2 from an external recording medium.

[Processing of standing motion support device 100A]
FIG. 20 shows a flowchart of processing of the standing operation support device 100A.

The process of the standing motion support device 100A includes the processes of steps S110 to S150 and further includes the process of step S160, similarly to the process of the standing motion support device 100 shown in FIG. 11A.

(Step S160)
The knee angle measuring unit 108 measures the knee joint angle of the user. The measured knee joint angle is a value (for example, an average value, a minimum value, a maximum value, etc.) obtained from the knee joint angles of both legs of the user, similar to the myoelectric value. The user's knee joint angle measured in this way is used in the process of step S130, more specifically, the process of step S132 shown in FIG. 11B. That is, the processing of the standing operation support device 100A according to this modification includes the processing of steps S131 to S134 shown in FIG. 11B. However, in the process of the standing motion support device 100A according to the present modification, the specific process (step S132) of determining whether or not the tibialis anterior muscle in the determination unit 105 is active as compared with the first embodiment. Content is different.

FIG. 21 shows an example of detailed processing in step S132 according to this modification.

(Step S132a)
The determination unit 105 acquires the knee joint angle measured by the knee angle measurement unit 108.

(Step S132b)
The determination unit 105 determines whether or not the knee joint angle acquired in step S132a is equal to or less than the second threshold value θ2. Here, when it is determined that the knee joint angle acquired in step S132a is equal to or less than the second threshold value θ2, the determination unit 105 proceeds to the process of step S132c. On the other hand, if it is determined that the threshold value is larger than the second threshold value θ2, the determination unit 105 proceeds to the process of step S132d.

(Step S132c)
The determination unit 105 determines whether or not the myoelectric value of the tibialis anterior muscle acquired in step S131 is equal to or greater than the threshold value the set as the first threshold value. Here, when it is determined that the myoelectric value is equal to or higher than the threshold value the, the determination unit 105 determines that the tibialis anterior muscle is active, and performs the processes after step S133 shown in FIG. 11B. On the other hand, when it is determined that the myoelectric value is not equal to or higher than the threshold value the, the determination unit 105 determines that the tibialis anterior muscle is not active, and performs the processes after step S131 shown in FIG. 11B.

(Step S132d)
The determination unit 105 determines whether or not the myoelectric value of the tibialis anterior muscle acquired in step S131 is equal to or greater than the threshold value thb (the <thb) set as the first threshold value. Here, when it is determined that the myoelectric value is equal to or higher than the threshold value thb, the determination unit 105 determines that the tibialis anterior muscle is active, and performs the processes after step S133 shown in FIG. 11B. On the other hand, when it is determined that the myoelectric value is not equal to or higher than the threshold value thb, the determination unit 105 determines that the tibialis anterior muscle is not active, and performs the processes after step S131 shown in FIG. 11B.

Here, the process of step S132d may be omitted from the process shown in FIG.

FIG. 22 shows another example of the detailed processing of step S132 according to this modification.

(Step S132a)
The determination unit 105 acquires the knee joint angle measured by the knee angle measurement unit 108.

(Step S132b)
The determination unit 105 determines whether or not the knee joint angle acquired in step S132a is equal to or less than the second threshold value θ2. Here, when it is determined that the knee joint angle acquired in step S132a is equal to or less than the second threshold value θ2, the determination unit 105 proceeds to the process of step S132c. On the other hand, when it is determined that the threshold value is larger than the second threshold value θ2, the determination unit 105 determines that the tibialis anterior muscle is not active, and performs the processes after step S131 shown in FIG. 11B.

(Step S132c)
The determination unit 105 determines whether or not the myoelectric value of the tibialis anterior muscle acquired in step S131 is equal to or greater than the first threshold value. Here, when it is determined that the myoelectric value is equal to or higher than the first threshold value, the determination unit 105 determines that the tibialis anterior muscle is active, and performs the processes after step S133 shown in FIG. 11B. On the other hand, when it is determined that the myoelectric value is not equal to or higher than the first threshold value, the determination unit 105 determines that the tibialis anterior muscle is not active, and performs the processes after step S131 shown in FIG. 11B.

As described above, in step S132b, when the knee joint angle is not equal to or less than the second threshold value θ2, the determination unit 105 proceeds to the process of step S131 regardless of the value of the myoelectric value. That is, the determination unit 105 according to this modification has a first condition in which the measured myoelectric value is equal to or higher than the first threshold value and a second condition in which the measured knee joint angle is equal to or lower than the second threshold value. And, when both the third condition that the measured trunk forward tilt angle is equal to or higher than the third threshold value are satisfied, it is determined that the support of the user's standing motion can be started.

Further, the determination unit 105 may set the first threshold value so that the first threshold value continuously increases as the knee joint angle increases. For example, the determination unit 105 may set the first threshold value th1 by th1 = α × θ. Here, α is a positive constant and θ is the knee joint angle. For example, when the initial value of the first threshold value is 200 μV and the second threshold value θ2 is 90 deg, the value of α is determined to be 200/90 = 2.22.

Here, when the user tries to stand up, the myoelectric value of the lower leg and the forward tilt angle of the trunk change. Further, when the flowchart shown in FIG. 21 is processed, if the first threshold value is large, that is, if the user's knee joint angle is large, the user cannot easily stand up. In such a case, the user repeatedly attempts to stand up. As a result, the myoelectric value of the lower leg and the forward tilt angle of the trunk change periodically.

Therefore, the determination unit 105 is a notification signal for urging the user to bend the knee when the measured myoelectric value and the trunk forward tilt angle are periodically changing in step S130 of FIG. Is output.

FIG. 23 shows a more detailed flow chart of the process of step S130 of FIG.

(Step S201)
The determination unit 105 acquires the myoelectric value of the tibialis anterior muscle from the storage unit 104.

(Step S202)
The determination unit 105 further acquires the trunk forward tilt angle from the storage unit 104.

(Step S203)
The determination unit 105 determines whether or not the myoelectric value and the trunk forward tilt angle acquired in steps S201 and S201 fluctuate periodically.

(Step S204)
Here, when the determination unit 105 determines that the myoelectric value and the trunk forward tilt angle are periodically fluctuating (step S203YES), the determination unit 105 outputs a notification signal for urging the user to bend the knee. For example, the speaker receiving this notification signal outputs a voice prompting the user to bend his / her knees. Alternatively, the display receiving this notification signal displays a message prompting the user to bend his / her knees. As a result, the user bends his knees. That is, the user's knee joint angle becomes smaller.

(Step S132)
Next, the determination unit 105 determines whether or not the tibialis anterior muscle is active according to the flowchart shown in FIG. When the notification of step S204 is performed, the knee joint angle becomes small, and it is highly possible that the knee joint angle is equal to or less than the second threshold value. As a result, in step S132c, the determination unit 105 determines whether or not the myoelectric value is equal to or greater than the first threshold value the (the <thb). That is, the determination unit 105 compares the myoelectric value with the smaller first threshold value the. On the other hand, if the knee joint angle is not equal to or less than the second threshold value, in step S132d, the determination unit 105 determines whether or not the myoelectric value is equal to or greater than the first threshold value thb. That is, the determination unit 105 compares the myoelectric value with the large first threshold value thb. Then, in steps S132c and 132d, when the determination unit 105 determines that the myoelectric value is equal to or higher than the first threshold value (that is, YES in step S132), the process of step S140 shown in FIG. 20 is performed. That is, the support for the standing motion is started. On the other hand, in steps S132c and 132d, when the determination unit 105 determines that the myoelectric value is less than the first threshold value (that is, NO in step S132), the determination unit 105 starts from step S201 shown in FIG. Repeat the process.

In this way, when the myoelectric value of the lower leg and the forward tilt angle of the trunk change periodically, the user is trying to stand up, but because the knee joint angle is large, he / she may stand up. I can't do it, and I'm in a situation where I'm repeating that act. Therefore, in such a situation, as described above, a notification signal for urging the user to bend the knee is output. This notification signal presents the user with a voice or character urging the knee to bend. The presentation causes the user to bend his knees. When the knee bends, the first threshold becomes smaller and the first condition is more likely to be satisfied. As a result, it is determined that the support for the standing motion can be started, and the user can receive the support for the standing motion by the support mechanism 107 and can easily stand up.

[effect]
As described above, in this modified example, when the knee joint angle is large and the standing motion cannot be supported correctly, the first threshold value for determining the activity of the tibialis anterior muscle becomes large, so that it is determined that the patient is active. It becomes difficult to be done. That is, even if the myoelectric value of the tibialis anterior muscle is the same, it is possible to reduce the determination that the support for the standing motion can be started when the knee is extended rather than when it is bent. As a result, it is possible to suppress the failure of the user's fall and standing operation shown in FIGS. 15A and 15B.

In other words, in this modification, the first threshold value is set so that the smaller the measured knee joint angle, the smaller the first threshold value, and the first threshold value set according to the knee joint angle is set. It is used to determine whether or not it is possible to start supporting the user's standing motion. As a result, when the knee joint angle is large, the support for the user's standing motion is not started unless the user's lower leg has stronger rigidity, and when the knee joint angle is small, the rigidity of the user's lower leg is weak. Also, support for the user's standing motion is started. Therefore, the danger as in the example shown in FIG. 15A can be suppressed. That is, when the user extends the leg forward to increase the knee joint angle, the support for the standing motion is started even though the rigidity of the user's lower leg is not sufficiently strong, so that the user balances. It is possible to prevent the knee from collapsing and falling. In addition, it is possible to suppress the failure of the standing operation as in the example shown in FIG. 15B. That is, when the user extends the leg forward to increase the knee joint angle, the support for the standing motion is started even though the rigidity of the user's lower leg is not sufficiently strong, so that the user stands up. It is possible to prevent the knees from being stretched while sitting without being able to do so.

Alternatively, in this modified example, when the second condition that the measured knee joint angle is equal to or less than the second threshold value and the above-mentioned first condition and the third condition are both satisfied, the user It is determined that it is possible to start supporting the standing motion. As a result, when the knee joint angle is large, the support for the user's standing motion is not started, and when the knee joint angle is small, the support for the user's standing motion is started. Therefore, the danger as in the example shown in FIG. 15A can be suppressed, and the failure of the standing operation as in the example shown in FIG. 15B can be suppressed.

(Modification 2)
In this modified example, unlike the first embodiment and the first modified example, the muscle used to determine whether or not the tibialis anterior muscle is active based on the trunk thigh angle and the knee joint angle during standing motion support. The first threshold value th1 of the electric value is changed. The trunk thigh angle is the angle between the thigh and the trunk.

[Device configuration]
FIG. 24 shows an example of a functional block diagram of the standing motion support device according to this modified example. The standing motion support device 100B according to this modification includes each component of the standing motion support device 100A shown in FIG. 13, and further includes a thigh angle measuring unit 110 for measuring the thigh angle.

[Thigh angle measuring unit 110]
Like the trunk angle measuring unit 102, the thigh angle measuring unit 110 includes, for example, a 9-axis sensor, and measures the thigh angle of the user. For example, the thigh angle measuring unit 110 has two 9-axis sensors, one 9-axis sensor is placed on the thigh of the user's right leg and the other 9-axis sensor is placed on the thigh of the user's left leg. .. Then, the thigh angle measuring unit 110 measures the average value, the minimum value, or the maximum value of the rotation angles about the y-axis obtained by these 9-axis sensors as the thigh angle of the user. The thigh angle is, for example, the angle between the vertical direction and the user's thigh, which is about 180 deg when the user is standing and about 90 deg when the user is seated.

The thigh angle measured by the thigh angle measuring unit 110 may be an angle calculated using a measured value directly obtained from the 9-axis sensor, and is calculated using a value corresponding to the measured value. It may be an angle. The value corresponding to the measured value is a value obtained by performing processing such as amplification, rectification, or filtering on the directly obtained measured value.

[Measurement processing unit 109]
The measurement processing unit 109 according to this modification performs the same processing as in the first embodiment, and calculates the trunk-thigh angle, which is the angle between the user's trunk and thigh. That is, the measurement processing unit 109 subtracts the user's trunk forward tilt angle measured by the trunk angle measuring unit 102 from the user's thigh angle measured by the thigh angle measuring unit 110, thereby causing the above-mentioned trunk. Calculate the thigh angle. As a result, the trunk and thigh angles are measured. Then, the measurement processing unit 109 notifies the determination unit 105 of the measured trunk thigh angle.

That is, the standing motion support device 100B according to the present modification includes a fourth sensor that measures the trunk thigh angle, which is the angle between the user's trunk and thigh. The fourth sensor is composed of some functions of the trunk angle measuring unit 102, the thigh angle measuring unit 110, and the measuring processing unit 109.

[Determination unit 105]
The determination unit 105 according to this modification performs the same processing as in the first embodiment, and based on the changes in the knee joint angle and the trunk thigh angle measured during the standing motion, the first threshold value th1 To change. Specifically, the determination unit 105 changes the first threshold value th1 to a larger value when the rate of change of the trunk thigh angle measured during the standing motion is larger than the rate of change of the knee joint angle.

That is, when the support mechanism 107 supports the standing motion, the determination unit 105 calculates the rate of change of the user's knee joint angle measured by the knee angle measurement unit 108 and notifies the measurement processing unit 109. Calculate the rate of change of the trunk and thigh angle. Then, the determination unit 105 determines the maximum rate of change of the knee joint angle and the maximum rate of change of the trunk and thigh angle when the standing motion is supported, that is, when the user is performing the standing motion. To compare. As a result, the determination unit 105 changes the first threshold value th1 to a larger value when the maximum rate of change of the trunk thigh angle is larger than the maximum rate of change of the knee joint angle. The changed first threshold value th1 is used to determine the start of support for the user's next standing motion.

FIG. 25 shows an example in which the user loses balance while the standing motion is supported.

For example, when the support start timing of the standing motion is too early, as shown in FIG. 25, the user does not yet have strong rigidity in the lower leg at that timing, so that the balance is lost immediately after the support start. At this time, the trunk thigh angle φ tends to fluctuate more than the knee joint angle θ.

FIG. 26 shows an example of changes in the knee joint angle θ and the trunk thigh angle φ when the standing motion is supported.

As shown in FIG. 26, when the timing of the support start of the standing operation is appropriate, the user can stably perform the standing operation. In this case, both the trunk thigh angle φ and the knee joint angle θ gradually increase. However, if the timing of starting the support for the standing motion is too early, the user performs an unstable standing motion and loses the balance. At this time, the trunk thigh angle φ of the user fluctuates greatly as compared with the stable normal standing operation. That is, the trunk thigh angle φ increases more rapidly than the knee joint angle θ.

However, in the standing motion support device 100B according to this modification, when the rate of change of the trunk thigh angle φ is larger than the rate of change of the knee joint angle θ, the first threshold th1 is changed to a larger value. .. Therefore, when the support for the standing motion is started next time, the timing for starting the support can be delayed, and the support for the standing motion can be started at an appropriate timing.

[Processing of standing motion support device 100B]
FIG. 27 shows a flowchart of processing of the standing operation support device 100B according to this modification.

The process of the standing motion support device 100B includes the processes of steps S110 to S150 and further includes the processes of steps S170 and S180, similarly to the process of the standing motion support device 100 shown in FIG. 11A.

(Step S170)
The standing motion support device 100B includes the thigh angle, the trunk forward tilt angle, and the knee joint angle when the standing motion is supported by the thigh angle measuring unit 110, the trunk angle measuring unit 102, and the knee angle measuring unit 108. To measure. It should be noted that these angles are measured, for example, each time the above-mentioned second time interval elapses. Further, at this time, the measurement processing unit 109 calculates the trunk thigh angle corresponding to each set of the thigh angle and the trunk forward tilt angle measured at the same timing. Thereby, for example, the trunk thigh angle and the knee joint angle are measured for each passage of the above-mentioned second time interval.

(Step S180)
The determination unit 105 determines whether or not the tibialis anterior muscle is active based on the respective rate of change of the trunk thigh angle and the knee joint angle during the standing motion measured in step S170. Perform th1 change processing.

[Details of processing of determination unit 105]
FIG. 28 shows a more detailed flow chart of the process of step S180 of FIG. 27.

(Step S181)
The determination unit 105 acquires the trunk thigh angle when the standing motion is supported from the measurement processing unit 109, and obtains the knee joint angle when the standing motion is supported from the knee angle measuring unit 108. get. When the support for the standing motion is provided, for example, it is a period from the start of the support for the standing motion to the elapse of a predetermined time. That is, during this period, the determination unit 105 acquires the trunk thigh angle and the knee joint angle at each passage of the above-mentioned second time interval.

(Step S182)
The determination unit 105 determines whether or not the trunk-thigh angle is larger than the knee joint angle when the standing motion is supported. If it is determined that the fluctuation of the trunk thigh angle is large, the determination unit 105 proceeds to step S183, and if it is determined that the fluctuation of the trunk thigh angle is not large, the determination unit 105 changes the first threshold value. End the process.

Specifically, the determination unit 105 determines whether or not the maximum rate of change of the trunk thigh angle when the support for the standing motion is performed is larger than the maximum rate of change of the knee joint angle at that time. judge. Alternatively, the determination unit 105 may determine that the change in the trunk thigh angle is large when the trunk thigh angle changes significantly by a predetermined value or more with respect to the change in the knee joint angle in the predetermined time width.

Further, in the determination in step S182, the determination unit 105 may make the determination only from the trunk and thigh angles of the user. Specifically, the determination unit 105 determines that the change in the trunk thigh angle is large when the change in the trunk thigh angle in a predetermined time width is larger than the threshold value determined in advance. In addition, if the user loses balance during the standing operation, the user's body sways back and forth. Therefore, the determination unit 105 may determine that the change in the trunk thigh angle is large when the change in the trunk forward tilt angle is not a monotonous increase but has an extreme value.

In this way, by observing the changes in the trunk thigh angle and the knee joint angle of the user when the standing motion is supported, it can be determined whether or not the standing motion is correctly supported by the user.

(Step S183)
When it is determined that the fluctuation of the trunk thigh angle is large, that is, when it is determined that the user is not able to support the correct standing motion, the determination unit 105 increases the first threshold value th1 of the myoelectric value by a predetermined value. To do.

[effect]
As described above, in this modification, when the fluctuation of the trunk thigh angle at the time of supporting the standing motion is large, the first threshold value th1 used for determining the support start of the next standing motion is significantly changed. Therefore, in the next standing motion, the support for the standing motion is not started unless a larger rigidity is generated in the lower leg. Therefore, it is possible to start the support for the standing motion at a more appropriate timing, and it is possible to reduce the risk that the user loses the balance when the standing motion is supported.

That is, when the rate of change of the trunk thigh angle measured during the standing motion is larger than the rate of change of the knee joint angle, it is assumed that the user is in an unstable state during the standing motion. Therefore, in this modified example, when the rate of change of the trunk thigh angle measured during the standing motion is larger than the rate of change of the knee joint angle, the first threshold value is changed to a larger value. As a result, the next time the user performs the standing operation, the support for the standing operation is started at the timing determined by using the changed first threshold value. Therefore, the timing at which the support for the standing motion is started can be delayed, and as a result, the user can stand up in a more stable state.

(Other embodiments)
The standing motion support device according to one or more embodiments has been described above based on each embodiment and each modification, but the present disclosure is not limited to these embodiments and each modification. Absent. As long as it does not deviate from the gist of the present disclosure, various modifications that can be conceived by those skilled in the art are applied to each of the above embodiments or examples, and a form constructed by combining the components of each embodiment and each modification is also available. , May be included within the scope of this disclosure.

For example, in each of the above-described embodiments and modifications, as shown in FIGS. 11A, 20 and 27, whether or not there is a request to start the support for the standing motion after it is determined that the support for the standing motion can be started. However, the order of these determinations may be reversed.

Further, in each of the above-described embodiments and modifications, specific numerical values of the first threshold value, the second threshold value, and the third threshold value are shown, but these numerical values are examples, and the respective threshold values are described above. Is not limited to these numerical values, and may be any numerical value.

Further, in each of the above-described embodiments and modifications, the myoelectric value of the tibialis anterior muscle is measured, but the myoelectric value of another muscle such as the vastus medialis muscle may be measured instead of the tibialis anterior muscle. Moreover, you may measure only the myoelectric value of the right leg or the left leg without measuring the myoelectric value of both legs. Similarly, only the thigh angle of the right leg or the left leg may be measured without measuring the thigh angle of both legs. For example, the myoelectric value or thigh angle of the user's dominant leg may be measured.

Further, in the second modification, in order to determine whether or not the fluctuation of the trunk thigh angle is large, the maximum rate of change of the trunk thigh angle during the standing motion is the maximum change of the knee joint angle during the standing motion. It was judged whether or not it was larger than the rate. However, the determination method is not limited to such a determination method, and it may be determined whether or not the fluctuation of the trunk-thigh angle is large by another determination method. For example, it is determined whether or not the average rate of change of the trunk thigh angle during a part of the period during which the standing motion is performed is larger than the average rate of change of the knee joint angle during a part of the period. May be good. A part of the period may be an intermediate period excluding the beginning and the end of the period in which the standing motion is performed.

In each of the above-described embodiments and modifications, each component may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. Here, the software program that realizes the standing operation support device of each of the above-described embodiments or modifications is the flowcharts shown in FIGS. 1B, 11A, 11B, 12B, 20 to 23, 27, and 28. It is a program that causes a computer to execute each step included in.

Further, in the present disclosure, all or a part of a unit, an apparatus, a member or a part, or all or a part of the functional blocks of the block diagram shown in FIGS. 1A, 2, 12A, 13 and 24. It may be executed by one or more electronic circuits including semiconductor devices, semiconductor integrated circuits (ICs), or LSIs (large scale integration). The LSI or IC may be integrated on one chip, or may be configured by combining a plurality of chips. For example, functional blocks other than the storage element may be integrated on one chip. Here, it is called an LSI or an IC, but the name changes depending on the degree of integration, and it may be called a system LSI, a VLSI (very large scale integration), or a ULSI (ultra large scale integration). A Field Programmable Gate Array (FPGA), which is programmed after the LSI is manufactured, or a reconfigurable logistic device that can reconfigure the junction relationship inside the LSI or set up the circuit partition inside the LSI can also be used for the same purpose.

Further, all or part of the function or operation of a unit, device, member or part can be performed by software processing. In this case, the software is recorded on one or more ROMs, optical disks, non-temporary recording media such as hard disk drives, and is identified by the software when it is executed by a processor. Functions are performed by the processor and peripherals. The system or device may include one or more non-temporary recording media on which the software is recorded, a processor, and the required hardware device, such as an interface.

The standing motion support device according to the present disclosure can be applied to, for example, an assist suit or a robot that supports the standing motion.

10, 100, 100A, 100B Standing motion support device 11 1st sensor 12 2nd sensor 15 Processor 17,107 Support mechanism 101 Myoelectric measurement unit 102 Trunk angle measurement unit 103 Timer 104 Storage unit 105 Judgment unit 106 Support request Unit 108 Knee angle measurement unit 109 Measurement processing unit 110 Thigh angle measurement unit

Claims (8)

The first sensor that measures the myoelectric value of the user's lower leg,
A second sensor that measures the knee joint angle of the user,
A third sensor that measures the forward tilt angle of the user's trunk,
At least, the first condition in which the measured myoelectric value is equal to or higher than the first threshold value, the second condition in which the measured knee joint angle is equal to or lower than the second threshold value, and the measured front of the trunk. When it is determined whether or not it is possible to start the support of the standing motion, which is the motion of standing up from the sitting state of the user , based on the third condition that the tilt angle is equal to or higher than the third threshold value, and it is determined that it is possible. With a processor that outputs an instruction signal,
A support mechanism for starting support for the user's standing operation when the instruction signal is output from the processor is provided.
The trunk forward tilt angle is an angle between the vertical direction and the user's trunk, and is an angle that increases as the trunk falls forward of the user.
Standing motion support device. The first sensor that measures the myoelectric value of the user's lower leg,
A second sensor that measures the knee joint angle of the user,
A third sensor that measures the forward tilt angle of the user's trunk,
The first threshold value is set so that the smaller the measured knee joint angle, the smaller the first threshold value, and the first condition that the measured myoelectric value is equal to or higher than the first threshold value. Based on the third condition that the measured forward tilt angle of the trunk is equal to or greater than the third threshold value, whether or not it is possible to start supporting the standing motion, which is the motion in which the user stands up from the sitting state. And a processor that outputs an instruction signal when it is determined that it is possible
A support mechanism for starting support for the user's standing operation when the instruction signal is output from the processor is provided.
The trunk forward tilt angle is an angle between the vertical direction and the user's trunk, and is an angle that increases as the trunk falls forward of the user.
Standing motion support device. The processor further
The standing motion support according to claim 2 , which outputs a notification signal for prompting the user to bend the knee when the measured myoelectric value and the trunk forward tilt angle are changed periodically. apparatus. The standing motion support device further
A fourth sensor for measuring the trunk-thigh angle, which is the angle between the user's trunk and thigh, is provided.
The processor
The standing motion support device according to any one of claims 1 to 3 , which changes the first threshold value based on the respective changes in the knee joint angle and the trunk thigh angle measured during the standing motion. The processor
The standing motion support according to claim 4 , wherein when the rate of change of the trunk thigh angle measured during the standing motion is larger than the rate of change of the knee joint angle, the first threshold value is changed to a larger value. apparatus. The first sensor that measures the myoelectric value of the user's lower leg,
A second sensor that measures the knee joint angle of the user,
A third sensor that measures the forward tilt angle of the user's trunk,
At least, the first condition in which the measured myoelectric value is equal to or higher than the first threshold value, the second condition in which the measured knee joint angle is equal to or lower than the second threshold value, and the measured front of the trunk. When it is determined whether or not it is possible to start the support of the standing motion, which is the motion of standing up from the sitting state of the user , based on the third condition that the tilt angle is equal to or higher than the third threshold value, and it is determined that it is possible. Also equipped with a processor that outputs an instruction signal to the support mechanism that supports the standing operation .
The trunk forward tilt angle is an angle between the vertical direction and the user's trunk, and is an angle that increases as the trunk falls forward of the user.
Standing motion support device. The first sensor measures the myoelectric value of the user's lower leg and
The second sensor measures the knee joint angle of the user and
A third sensor measures the forward tilt angle of the user's trunk and
The trunk forward tilt angle is an angle between the vertical direction and the user's trunk, and is an angle that increases as the trunk falls forward of the user.
The processor has a first condition in which the measured myoelectric value is equal to or higher than the first threshold value, a second condition in which the measured knee joint angle is equal to or lower than the second threshold value, and the measured trunk. Based on the third condition in which the forward tilt angle is equal to or greater than the third threshold value, it is determined whether or not it is possible to start supporting the standing motion, which is the motion in which the user stands from the sitting state.
A standing motion support method in which the support mechanism starts supporting the standing motion of the user when it is determined that it is possible. Get the myoelectric value of the user's lower leg,
Obtain the knee joint angle of the user and
Acquire the trunk forward tilt angle of the user,
The trunk forward tilt angle is an angle between the vertical direction and the user's trunk, and is an angle that increases as the trunk falls forward of the user.
At least, the first condition that the acquired myoelectric value is equal to or more than the first threshold value, the second condition that the measured knee joint angle is equal to or less than the second threshold value, and the measured front of the trunk. When it is determined whether or not the support start of the standing motion, which is the motion of standing up from the sitting state of the user, is possible based on the third condition that the tilt angle is equal to or higher than the third threshold value, and it is determined that the support is possible. A program for causing a computer to output an instruction signal to a support mechanism that supports the standing motion.

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