JP7354965B2 - walking aid device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a walking assist device, and for example, to a walking assist device that is attached to a user's leg.

Patent Document 1 describes a walking assist device that is worn by a user. The walking assist device of Patent Document 1 includes a thigh link, a lower leg link, a sensor, a motor, and a controller, and includes a damper that generates a resistance force against rotation of the lower leg link in the knee bending direction.

Patent No. 5316708

There is a need to widen the effective range of a damper used when walking while wearing a walking assist device, and to realize a walking assist device that can use the damper not only to assist when walking but also to assist when sitting.

The present invention has been made to solve such problems, and provides a walking assist device that can assist not only walking but also sitting.

The walking assist device according to the present embodiment is a walking assist device that is attached to a leg of a user, and includes a damper that applies a resistance force in a bending direction of a knee joint of the leg, and a switching timing in the walking cycle of the user. and a control unit that switches the mode of the damper according to the switching timing so that the first mode and the second mode in which the resistance force is stronger than the first mode are alternately repeated, The damper includes a first damper section that operates when the knee angle is within a predetermined knee angle, and a second damper section that operates when the knee angle is larger than the predetermined knee angle. With such a configuration, it is possible to provide a walking assist device that can assist not only walking but also sitting.

According to this embodiment, it is possible to provide a walking assist device that can assist not only walking but also sitting.

FIG. 1 is a front view illustrating a walking assist device according to an embodiment. FIG. 1 is a side view illustrating a walking assist device according to an embodiment. (a) to (c) are diagrams illustrating dampers in the walking assist device according to the embodiment. FIG. 2 is a perspective view illustrating a damper in the walking assist device according to the embodiment. FIG. 1 is a block diagram illustrating a control system of a walking assist device according to an embodiment. FIG. 3 is a diagram illustrating walking motion and mode switching timing in a walking cycle using the walking assist device according to the embodiment.

The present invention will be described below through embodiments, but the claimed invention is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are essential as means for solving the problem. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanation will be omitted as necessary.

(Embodiment)
A walking assist device according to an embodiment will be described. The walking assist device of this embodiment is attached to, for example, the leg of a trainee who performs walking training, including the knee joint. A trainee who is a user performs walking training with the walking assist device attached to the leg. First, the configuration of the walking assist device of this embodiment will be explained. After that, the operation of the walking assist device will be explained.

FIG. 1 is a front view illustrating a walking assist device according to an embodiment. FIG. 2 is a side view illustrating the walking assist device according to the embodiment. FIGS. 3(a) to 3(c) are diagrams illustrating dampers in the walking assist device according to the embodiment. FIG. 4 is a perspective view illustrating a damper in the walking assist device according to the embodiment. FIG. 5 is a block diagram illustrating a control system of the walking assist device according to the embodiment.

As shown in FIGS. 1 to 5, the walking assist device 1 includes an upper leg supporter 11, a lower leg supporter 12, an upper leg frame 13, a lower leg frame 14, a damper 15, a sensor 17, and a control section 18. The damper 15 includes a first damper section 15a and a second damper section 15b. A short leg orthosis may be attached to the lower side of the walking aid device 1. The walking assist device 1 is attached to a user's leg. Each configuration of the walking assist device 1 will be explained below.

<Upper leg supporter and lower leg supporter>
The upper leg supporter 11 is attached so as to be wrapped around the upper leg of the user's leg, and the lower leg supporter 12 is attached so as to be wrapped around the lower leg of the user's leg. Therefore, the upper leg supporter 11 and the lower leg supporter 12 are arranged around the knee joint, specifically, over the upper leg and the lower leg. Note that the upper leg indicates the part from the hip joint to the knee joint, and the lower leg indicates the part from the knee joint to the ankle joint. The lower leg includes the shin. The part below the ankle joint, that is, the part toward the tip of the leg, is the foot.

The upper leg supporter 11 and the lower leg supporter 12 are made of a stretchable material such as a resin material or a fiber material. The upper leg supporter 11 and the lower leg supporter 12 are wrapped around the upper leg and lower leg, respectively, to allow the walking assist device 1 to be worn. The upper leg supporter 11 and the lower leg supporter 12 may have hook-and-loop fasteners 11a and 12a for attachment to the upper leg and lower leg. The user wraps the upper leg supporter 11 and the lower leg supporter 12 around the legs and secures them with hook-and-loop fasteners 11a and 12a.

The hook and loop fastener 11a is provided on the front side of the upper leg. The hook and loop fastener 12a is provided on the front side of the lower leg. By using the hook-and-loop fasteners 11a and 12a, the user can easily attach and detach the walking aid device 1. Furthermore, it is possible to prevent the walking assist device 1 from shifting from the user's knee joint. The hook-and-loop fasteners 11a and 12a allow the user to adjust the degree of compression. Furthermore, a fixing band may be provided to prevent the hook-and-loop fasteners 11a and 12a from coming off and the upper leg supporter 11 and lower leg supporter 12 from shifting.

Note that fixing of the walking aid device 1 to the leg portion is not limited to the hook-and-loop fasteners 11a and 12a. For example, the walking aid device 1 may be fixed to the upper and lower legs using a fixing means such as a belt, button, pin, or band. Even if such a fixing means is used, the user can wear the walking assist device 1.

<Upper leg frame and lower leg frame>
An upper leg frame 13 is attached to the side of the upper leg supporter 11. The upper leg frame 13 is arranged along the upper leg. A lower leg frame 14 is attached to the side of the lower leg supporter 12. The lower leg frame 14 is arranged along the lower leg. The upper leg frame 13 and the lower leg frame 14 are connected via a damper 15. Specifically, the damper 15 is arranged at the height of the knee joint so that the rotation axis Ax of the damper 15 substantially coincides with the axis of the knee joint. The upper leg frame 13 and the lower leg frame 14 constitute a link mechanism rotatable around the rotation axis Ax of the damper 15.

<Damper>
The damper 15 including the first damper part 15a and the second damper part 15b provides a resistance force in the bending direction of the knee joint in the user's leg. The bending direction is the direction in which the knee joint bends in the direction of rotation of the knee joint. The first damper section 15a and the second damper section 15b are located on the sides of the knee joint. The first damper section 15a and the second damper section 15b decelerate the rotation of the knee joint in the bending direction by using, for example, viscous resistance of a fluid such as oil, elastic resistance of a spring, frictional resistance of a disk, etc. . At least one of the first damper section 15a and the second damper section 15b is connected to the control section 18 via a wired or wireless communication line.

As shown in FIG. 3(a), the bending angle at which the lower leg is bent from the state where the upper leg and lower leg are straight and the knee joint is extended is called the knee angle θ. The first damper portion 15a operates when the knee angle is within a predetermined knee angle θ1. On the other hand, the second damper portion 15b operates at a knee angle larger than the predetermined knee angle θ1.

The first damper section 15a is, for example, a stroke damper, and may include an absorber. As shown in FIGS. 3(a) to 3(c) and FIG. 4, for example, the first damper portion 15a includes a cylinder TU, a shaft SH that moves linearly inside the cylinder TU, and a shaft SH that moves linearly inside the cylinder TU. It has a stopper ST that comes into contact with the tip of the protruding shaft SH. By pressing the cylindrical body TU against the stopper ST via the shaft SH, the shaft SH is moved into the inside of the cylindrical body TU. The first damper portion 15a generates a resistance force when the shaft SH moves into the cylindrical body TU. The first damper section 15a operates as a damper up to the limit where the shaft SH can move into the cylindrical body TU.

As shown in FIGS. 3A and 3B, as the knee angle θ increases, the amount by which the shaft SH moves into the cylindrical body TU increases. The knee angle θ at the limit where the shaft SH can move inside the cylindrical body TU is set to a predetermined knee angle θ1. Then, when the user walks, the knee angle θ is set to be within a predetermined knee angle θ1. Then, the first damper portion 15a operates as a damper when walking within the predetermined knee angle θ1. However, in that case, the first damper portion 15a cannot operate as a damper when the passenger is seated, where the knee angle θ>θ1 is greater than the predetermined knee angle θ1.

In the present embodiment, the range of the knee angle θ in which the first damper portion 15a exerts its damper effect is narrower than that of the second damper portion 15b. When the first damper section 15a is a stroke damper, the first damper section 15a has a simple structure using a shaft SH that moves linearly. Therefore, the first damper part 15a has higher durability than the second damper part 15b, and can be used a larger number of times.

The second damper section 15b is, for example, a rotary damper. For example, the second damper portion 15b has a stopper ST fixed to the point of action of the rotary damper. That is, when the stopper ST rotates the rotary damper, the second damper section 15b operates as a damper. The second damper portion 15b does not operate as a damper when walking within a predetermined knee angle θ1. This is because the first damper portion 15a absorbs the force that presses the stopper ST. However, when the shaft SH moves to the limit where it can move inside the cylindrical body TU, the cylindrical body TU and the shaft SH become integrated and push the stopper ST. Thereby, the stopper ST rotates the rotary damper. Therefore, the second damper portion 15b operates as a damper when the passenger is seated, where the knee angle θ>θ1, which is larger than the predetermined knee angle θ1.

In this way, in the first damper section 15a, the integrated cylindrical body TU and shaft SH start pushing the stopper ST fixed to the second damper section 15b at a predetermined knee angle θ1. Then, when the first damper section 15a presses the stopper ST, the second damper section 15b is activated. Note that the first damper section 15a and the second damper section 15b are arranged in series directly connected in the rotation direction, but the present invention is not limited to this. They may be arranged in parallel.

In this embodiment, the second damper part 15b has a wider range of knee angles θ in which it exhibits a damper effect than the first damper part 15a. On the other hand, when the second damper section 15b includes a rotary damper, a container including a packing such as rubber is filled with oil, and the second damper section 15b operates as a damper due to the viscous resistance of the fluid such as oil. Since the second damper part 15b has its packing replaced frequently, its durability is lower than that of the first damper part 15a, and the number of times it can be used is small.

<Sensor>
As shown in FIG. 5, the sensor 17 is connected to the control unit 18 via a wired or wireless communication line. The sensor 17 detects the timing of the user's walking motion. Specifically, the sensor 17 is provided to detect switching timing in a walking cycle. For example, the sensor 17 detects the knee angle θ or the angle between the ground and the lower leg, and outputs the detected angle to the control unit 18 as a detection result. The control unit 18 switches the mode of the damper 15 based on the detection result by the sensor 17.

Specifically, the control unit 18 switches the mode of the damper 15 based on the lower knee angle or the angle between the ground and the lower leg. That is, the control unit 18 switches the mode of the damper 15 based on the timing signal output from the sensor 17. Thereby, the control unit 18 switches the mode of the damper 15 at a certain timing in the walking cycle. Power is supplied to the sensor 17 and the control unit 18 by a battery (not shown) mounted on the walking assist device 1.

Various types of sensors can be used as the sensor 17. A specific example of the sensor 17 will be described below.

The sensor 17 may be, for example, a gyro sensor that detects the angle of the lower leg (shin) with respect to the ground. Further, the sensor 17 may be an angle sensor that detects the angle of the leg, that is, the angle between the upper leg and the lower leg with the knee joint in between. Further, the sensor 17 may be an angle sensor that detects the knee angle θ at which the lower leg is bent from a state where the upper leg and the lower leg are linearly extended and the knee joint is extended. The sensor 17 may be an angular velocity sensor that detects the angular velocity of the lower leg angle, the leg angle, and the knee angle θ.

The sensor 17 may be a distance sensor that detects the distance between a predetermined position of the leg and the ground. The predetermined position of the leg is, for example, a shoe, the sole of the foot, or the like. For example, a distance measuring sensor attached to a shoe, a foot, or the vicinity thereof can be used as the sensor 17. Since the distance from shoes, soles, etc. to the ground changes depending on the walking motion, it is possible to detect waveforms corresponding to the walking cycle. Note that an optical sensor can be used as the distance measurement sensor. Furthermore, the ground includes the floor surface.

The sensor 17 detects a waveform according to the walking cycle from the detected angle, angular velocity, distance, etc. That is, the detected angle, angular velocity, distance, etc. change periodically according to the walking cycle. The sensor 17 detects walking timing based on the detected angle, angular velocity, distance, etc.

For example, the control unit 18 may compare the output value of the sensor 17 with a threshold value and switch the mode of the damper 15 according to the comparison result. For example, the control unit 18 performs mode switching in response to a timing signal indicating the timing at which the output value of the sensor 17 exceeds a threshold value or falls below a threshold value.

In addition, in the damper 15, a first threshold value (for example, a first angle of the lower leg) for detecting the switching timing to switch from the first mode to the second mode, and a switching timing to switch from the second mode to the first mode are detected. A second threshold value (for example, a second angle of the lower leg) may be set.

Further, the sensor 17 may be a ground contact timing sensor that detects the timing of the sole of the foot touching the ground. The sensor 17 can detect walking timing based on the detected ground contact timing. For example, the sensor 17 detects the switching timing by adding or subtracting the time from the ground contact timing to the timing of each mode switching in advance.

Furthermore, the sensor 17 may be an image sensor that images the leg. In that case, the sensor 17 images the state of the leg from outside the walking assist device 1. Walking timing can be detected from the imaged state of the leg. In addition, when the sensor 17 is arranged externally, the walking assistance device 1 only needs to include a receiving section that receives a signal indicating the switching timing from the external sensor 17.

Further, the switching timing may be detected by combining a plurality of sensors 17. For example, the sensor 17 may include both a first sensor provided to detect the angle of the lower leg and a second sensor provided to detect the distance from the sole of the foot to the floor. Of course, the specific example of the sensor 17 is not limited to the above example. It is preferable that the sensor 17 is implemented in the walking aid device 1. Alternatively, the sensor 17 may be mounted outside the walking aid device 1.

<Control unit>
The control unit 18 is connected to the damper 15 and the sensor 17 via a wired or wireless communication line. The control unit 18 controls the damper 15 based on the switching timing output from the sensor 17. The control unit 18 switches the mode of the damper 15.

The control unit 18 switches the mode of the damper 15 according to the switching timing so that the first mode and the second mode are alternately repeated. For example, in the first mode, the damper 15 is turned off, resulting in a free mode in which no resistance is applied in the bending direction. In the second mode, the damper 15 is turned on and becomes a damper mode that provides resistance in the bending direction. Alternatively, for example, in the first mode, the damper 15 is switched to provide a small resistance force, and in the second mode, the damper 15 is switched to provide a large resistance force. The first damper part 15a and the second damper part 15b included in the damper 15 operate as a damper according to the knee angle θ. During the walking cycle, the first damper portion 15a of the damper 15 mainly operates.

<Operation>
Next, the operation of the walking assist device 1 will be explained. First, we will explain the movement in the walking cycle. After that, the sitting operation will be explained.

FIG. 6 is a diagram illustrating walking motion and mode switching timing in a walking cycle using the walking assist device 1 according to the embodiment. First, one walking cycle including a swing phase and a stance phase will be explained with reference to FIG. Next, the timing of walking motion and mode switching will be explained.

<1 walk cycle>
As shown in FIG. 6, one walking cycle includes a total of two steps: one step with the left leg and one step with the right leg. In FIG. 6, one walking cycle is shown in the order of (a) to (m). After timing (m), the process returns to timing (a) and the next walking cycle begins. In FIG. 6, the swing phase occurs at timings (a) to (g), and the stance phase occurs at timings (h) to (m).

The swing phase is a state in which the sole of the leg on which the walking assist device 1 is attached is off the ground, and the stance phase is a state in which the sole of the leg on which the walking assist device 1 is attached is in contact with the ground. The sole of the foot touches the ground between the timing of (g) and (h), and the sole of the foot leaves the ground at the timing of returning from (m) to (a). The timings of (a) to (c) are the flexion period when the flexion angle of the knee joint becomes large, and the timings of (d) to (g) are the extension period when the flexion angle of the knee joint becomes small. Note that the swing phase, stance phase, flexion phase, and extension phase are based on the affected leg on which the walking assist device 1 is attached.

<Bending direction>
Next, the timing of walking motion and mode switching in one walking cycle will be explained. First, the operation of the damper 15 that applies a resistance force in the bending direction of the knee joint will be explained. In the walking cycle, when the knee angle θ is within a predetermined knee angle θ1, the first damper portion 15a is activated. In the extension period, specifically, the first mode is switched to the second mode at the timing (f). Moreover, the second mode is switched to the first mode at the timing when the stance phase changes to the swing phase, specifically, between the timing (m) and the timing (a).

The first mode includes a free mode in which no resistance force is applied in the bending direction of the knee joint, or a mode in which a resistance force smaller than the second mode is applied. The second mode includes a damper mode that provides a resistance force in the bending direction of the knee joint, or a mode that provides a resistance force greater than the first mode.

During the swing phase, the affected leg does not need to support the user's weight. Therefore, during the swing phase, there is no need for the damper 15 to generate a resistance force against the knee joint, or even if it is generated, the resistance force may be small. Therefore, during almost the entire swing phase, the control unit 18 can set the first mode including the free mode in the bending direction. On the other hand, throughout the stance phase, the control unit 18 sets the second mode to generate a resistance force on the damper 15 in the bending direction.

Further, in one walking cycle, only the first mode and the second mode are provided, and the control unit 18 alternately switches between the first mode and the second mode during the walking motion. That is, the control unit 18 controls the damper 15 based on the timing signal. For example, free mode and damper mode are controlled on and off. By doing so, appropriate control can be performed with a simple configuration. For example, if the walking motion varies from walk cycle to walk cycle, the switching timing detected by the sensor 17 may vary. Even in such a case, it is sufficient that the damper 15 is switched from the first mode to the second mode at a timing before switching from the swing phase to the stance phase, that is, at an arbitrary timing during the extension phase.

Specifically, the control unit 18 only needs to switch the mode at a predetermined timing between (d) and (g). Since the margin for the error in the switching timing detected by the sensor 17 can be widened, appropriate control can be achieved. Furthermore, during the extension phase, the knee joint gradually rotates from a flexed state in the direction of extension. Therefore, even if the damper 15 is in the second mode, no resistance force is generated. Therefore, mode switching can be performed without the damper 15 interfering with the user's walking motion.

Further, the damper 15 is free so as not to generate any resistance force in the direction of extension. Therefore, the user can freely extend the knee joint. Further, since there is no lock mode in which the damper 15 is locked between the second mode including the damper mode and the first mode including the free mode, it is possible to prevent the damper 15 from interfering with the walking movement. Since the second mode is transferred to the first mode without going through the lock mode, appropriate control can be easily performed.

The switching timing between the swing phase and the stance phase may be detected by the output of the sensor 17, and the swing phase may be set to the first mode and the stance phase may be set to the second mode. That is, the timing of changing from the swing phase to the stance phase and the timing of switching from the stance phase to the swing phase may be used as the timing for switching the mode of the damper 15.

Further, the switching between the first mode and the second mode may be abrupt or smooth. That is, the second mode may include a period in which the resistance force gradually increases from the resistance force in the first mode, or may include a period in which the resistance force gradually decreases to the resistance force in the first mode.

<Extension direction>
Next, the motion of the knee joint in the extension direction will be explained. In this embodiment, the motion in the extension direction is, for example, in free mode throughout the gait cycle. Note that the damper may be operated in the extension direction during a predetermined period of the walking cycle.

<Seated>
Next, the operation when sitting will be explained. As shown in FIG. 3(a), before the sitting motion starts, the knee angle θ is within a predetermined knee angle θ1. When the user starts sitting, the knee angle θ increases. At this time, until the knee angle θ reaches a predetermined knee angle θ1, the first damper portion 15a applies a resistance force in the bending direction to assist the user in sitting down.

Then, as shown in FIG. 3(b), when the knee angle θ reaches a predetermined knee angle θ1, the shaft SH moves to the limit where it can move inside the cylindrical body TU. As a result, the first damper portion 15a does not apply any resistance force in the bending direction and does not operate as a damper. On the other hand, a pushing force is applied to the stopper ST from the cylindrical body TU. Thereby, the second damper portion 15b applies a resistance force in the bending direction and operates as a damper.

As shown in FIG. 3C, when the knee angle θ is larger than the predetermined knee angle θ1, the second damper portion 15b applies a resistance force in the bending direction to assist the user in sitting down. In this way, the user wearing the walking assistance device 1 can sit down with the assistance of the walking assistance device 1.

Next, the effects of this embodiment will be explained. In the walking assist device 1 of the present embodiment, the damper 15 includes a first damper portion 15a that operates when walking with a knee angle θ1 or less, and a second damper portion 15a that operates when sitting at a knee angle θ larger than the predetermined knee angle θ1. A damper section 15b is included. Therefore, the walking assist device 1 can assist not only the user's walking motion but also the user's sitting motion.

Furthermore, since the angular range in which the first damper section 15a operates is narrow, if the first damper section 15a alone is used to assist the seating motion, a plurality of first damper sections 15a are required. On the other hand, since the angular range in which the second damper section 15b operates is wide, the second damper section 15b alone can assist in walking motion and sitting motion. However, since the durability of the second damper part 15b is lower than that of the first damper part 15a, it is necessary to replace the second damper part 15b frequently.

The walking aid device 1 of this embodiment combines a first damper section 15a that operates in a narrow range of angles but has high durability, and a second damper section 15b that operates in a wide range of angles but has low durability. . The first damper section 15a is activated when the user is walking, which is used a large number of times, and the second damper section 15b is activated when the user is seated, where the user's number of uses is less than when walking. Thereby, durability can be improved while suppressing the number of dampers. In addition, the weight can be reduced, and walking training can be performed in a manner close to normal.

Furthermore, if the predetermined knee angle θ1 is set to correspond to an action that deeply bends the knee joint, such as going up and down stairs, it can be applied not only to sitting action but also to going up and down stairs.

The resistance force of the first damper part 15a, the resistance force of the second damper part 15b, and the predetermined knee angle θ1 may be set according to the user. Therefore, walking training that suits the user's symptoms can be performed.

Note that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the spirit.

1 Walking aid device 11 Upper leg supports 11a, 12a Hook-and-loop fastener 12 Lower leg supporter 13 Upper leg frame 14 Lower leg frame 15 Damper 15a First damper section 15b Second damper section 17 Sensor 18 Control section Ax Rotation axis TU Cylindrical body SH Shaft ST Stopper

Claims (1)

A walking aid device that is attached to a user's leg,
a damper that applies a resistance force in the bending direction of the knee joint of the leg;
a sensor that detects switching timing in the user's walking cycle;
a control unit that switches a damper mode according to a switching timing so that a first mode and a second mode having a stronger resistance than the first mode are alternately repeated;
Equipped with
The damper includes a first damper portion that operates when the knee angle is within a predetermined knee angle;
a second damper section that operates at a knee angle greater than the predetermined knee angle;
including,
Walking aid device.

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