JP2021090513A - Walking state determination device - Google Patents

Abstract

To provide an easily attachable walking state determination device.SOLUTION: A walking state determination device 4 for determining a walking state of a person, includes: an ultrasonic sensor 4a to be attached at a prescribed part on one lower limb of a person for detecting a position of the other lower limb relative to the one lower limb and its change; and a computation unit 4b for determining a walking state of the person based on a detection result of the ultrasonic sensor 4a.SELECTED DRAWING: Figure 5

Description

The present invention relates to a walking state determination device.

In the walking training system used by the trainee to perform walking training, it is necessary to provide appropriate assistance according to the walking state of the trainee. Therefore, the walking state of the trainee during the training (for example, walking training is performed). It is necessary to accurately determine whether the state of the leg is a free leg or a standing leg. For example, Patent Document 1 describes a technique for determining the walking state of a trainee based on the detection results of an acceleration sensor and a pressure sensor attached to the foot and the sole of the foot.

Japanese Patent No. 6280488

However, in the configuration of Patent Document 1, it may be difficult to attach the sensor to the foot (that is, the portion beyond the ankle), especially when wearing shoes. Further, even if the sensor is attached to the foot, the wiring structure may become complicated.

The present invention has been made in view of the above background, and an object of the present invention is to provide a walking state determination device that can be easily attached.

The walking state determination device according to an embodiment of the present invention is a walking state determination device that determines a person's walking state, and is attached to a predetermined portion of one of the lower limbs of the person and said from one of the lower limbs. It includes an ultrasonic sensor that detects the position of the other lower limb and its change, and a calculation unit that determines the walking state of the person based on the detection result of the ultrasonic sensor. This walking state determination device does not need to be attached to the foot, and can be easily attached to any part of the lower limbs. Moreover, since it is not necessary to attach it to the foot, the complexity of the wiring structure is eliminated.

According to the present invention, it is possible to provide a walking state determination device that is easy to attach.

It is a perspective view which shows the schematic structure of the walking training system to which the walking state determination device which concerns on Embodiment 1 is applied. It is a front view which shows the schematic structure of the walking assist device. It is a perspective view which shows the schematic structure of the walking assist device attached to the leg part. It is a block diagram of a walking training system. It is a schematic diagram which shows the structure of the walking state determination device attached to the leg part. It is a figure which shows the relationship between the walking state of a trainee, and the position (distance and angle) of the other leg from one leg to which an ultrasonic sensor is attached. It is a figure which shows the distribution of the signal intensity acquired by the ultrasonic sensor in each walking state of a trainee. It is a flowchart which shows the walking state determination method by the walking state determination device. It is a figure which shows the relationship between the walking state of a trainee, and the position (height) from the ground of the leg to which the 2nd ultrasonic sensor provided in the walking state determination device which concerns on Embodiment 2 is attached. is there.

Hereinafter, the present invention will be described through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Moreover, not all of the configurations described in the embodiments are indispensable as means for solving the problem. In order to clarify the explanation, the following description and drawings have been omitted or simplified as appropriate. In each drawing, the same elements are designated by the same reference numerals, and duplicate explanations are omitted as necessary.

<Embodiment 1>
The walking state determination device according to the first embodiment is applied to a walking training system, and determines the walking state of a person (trainee). First, the configuration of the walking training system to which the walking state determination device according to the present embodiment is applied will be described.

FIG. 1 is a schematic diagram illustrating a configuration of a walking training system to which the walking state determination device according to the first embodiment is applied. As shown in FIG. 1, the walking training system 1 includes a walking assist device 2 attached to the leg of the trainee U, a training device 3 for performing walking training of the trainee U, and a walking state determination device 4. I have.

The walking assist device 2 is attached to, for example, the affected leg of the trainee U who performs walking training, and assists the trainer U in walking. The trainee U performs walking training with the walking assist device 2 attached to the knee joint. The walking assist device 2 applies a resistance force in the flexion direction of the knee joint.

The walking assist device 2 will be described in more detail with reference to FIGS. 2 and 3. FIG. 2 is a front view of the walking assist device 2. FIG. 3 is a perspective view showing a state in which the trainee U is wearing the walking assist device 2. FIG. 3 shows an example in which the trainee U wears the walking assist device 2 on the left leg.

The walking assist device 2 includes a supporter 21, a damper 22, an upper leg frame 23, and a lower leg frame 24. An ankle foot orthosis 25 (partially omitted in FIG. 2) may be attached to the lower side of the walking assist device 2. The supporter 21 is formed of a stretchable material such as a resin material or a fiber material. The supporter 21 is arranged in and around the knee joint, specifically, from the upper leg UL to the lower leg LL. The upper leg UL indicates a portion from the hip joint to the knee joint, and the lower leg LL indicates a portion from the knee joint to the ankle joint. The upper leg UL, lower leg LL, and foot palm FT are collectively referred to as the lower limbs.

The supporter 21 has a hook-and-loop fastener 21a for attaching the walking assist device 2 to the knee joint. The trainee U winds the supporter 21 around the legs and fixes it with the hook-and-loop fastener 21a. The hook-and-loop fasteners 21a are provided above and below the knee joint, specifically, on the anterior side of the upper leg UL and on the anterior side of the lower leg LL, respectively. By using the hook-and-loop fastener 21a, the walking assist device 2 can be easily attached and detached. Further, by using the hook-and-loop fastener 21a, it is possible to prevent the walking assist device 2 from being displaced from the knee joint of the trainee U. Further, by using the hook-and-loop fastener 21a, the trainee U can adjust the degree of compression applied to the knee joint. A fixing band 21b may be further provided in order to prevent the hook-and-loop fastener 21a from coming off or the supporter 21 from shifting.

An upper leg frame 23 and a lower leg frame 24 are attached to the side portion of the supporter 21. The upper leg frame 23 is arranged along the upper leg UL. The lower leg frame 24 is arranged along the lower leg LL. The upper leg frame 23 and the lower leg frame 24 are connected via a damper 22. The damper 22 is, for example, a rotary damper and is located on the side of the knee joint. Specifically, the damper 22 is arranged at the height of the knee joint so that the rotation axis Ax of the damper 22 substantially coincides with the axis of the knee joint. The upper leg frame 23 and the lower leg frame 24 form a link mechanism that can rotate around the rotation axis Ax of the damper 22.

The damper 22 provides resistance in the flexion direction of the knee joint. For example, the damper 22 uses the viscous resistance of a fluid such as oil to slow down the rotation of the knee joint in the flexion direction. The damper 22 is preferably a unidirectional damper that provides resistance in only one direction. The damper 22 is free so as not to give a resistance force in the extension direction of the knee joint. The damper 22 adjusts the resistance force by the control unit 28 described later.

An ankle foot orthosis 25 is provided below the supporter 21. As shown in FIG. 3, the ankle foot orthosis 25 is arranged along the lower leg LL of the trainee U. A foot flat frame 25a is provided at the lower end of the ankle foot orthosis 25. The foot flat frame 25a is fixed to the foot flat FT of the trainee U with a hook-and-loop fastener, a fixed band, or the like.

The configuration of the walking assist device 2 described above is an example, and is not limited to this. The walking assist device 2 may be attached to the legs of the trainee U and can assist the walking.

Returning to the description of FIG. The training device 3 includes a treadmill 31, a frame main body 32, a control device 35, and a display unit 36. The treadmill 31, the control device 35, and the display unit 36 are fixed to the frame body 32. The display unit 36 is arranged in front of the trainee U.

The treadmill 31 has a rotatable ring-shaped belt conveyor 311 for the trainee U to walk, and rotates the belt conveyor 311 at a set speed Vs. The trainee U rides on the belt conveyor 311 and walks according to the movement of the belt conveyor 311. The display unit 36 displays information such as training instructions, training menus, and training information (set speed, biological information, etc.) for the trainee U. For example, the display unit 36 may include a touch panel, in which case the trainee U can input various information via the display unit 36. Further, the training device 3 may have a camera or the like that captures the trainer U. As a result, the display unit 36 can display an image of the walking motion of the trainee U during training.

The control device 35 stores, for example, a CPU (Central Processing Unit) that performs arithmetic processing, control processing, etc., a ROM (Read Only Memory) in which arithmetic programs executed by the CPU, control programs, etc. are stored, various data, and the like. The hardware is composed mainly of a microcomputer including a RAM (Random Access Memory), an interface unit (I / F) for inputting / outputting signals to and from the outside, and the like. The CPU, ROM, RAM, and interface unit are connected to each other via a data bus or the like.

FIG. 4 is a block diagram of the walking training system 1. As shown in FIG. 4, the control device 35 is connected to the walking assist device 2 and the treadmill 31 via wiring or the like. The control device 35 controls the drive of the treadmill 31 based on the information regarding the walking state of the trainee U transmitted from the control unit 28 of the walking assist device 2. Further, the control device 35 displays training instructions, training menus, training information, etc. for the trainer U on the display unit 36 based on the information regarding the walking state of the trainer U transmitted from the control unit 28 of the walking assist device 2. Display information. The walking assist device 2 and the walking state determination device 4 are connected via wiring or the like. The walking state of the trainee is transmitted from the walking state determination device 4 to the control unit 28 of the walking assist device 2. The control unit 28 of the walking assist device 2 adjusts the resistance force of the damper 22 according to the walking state of the trainee U transmitted from the walking state determination device 4.

FIG. 5 is a schematic view showing the configuration of the walking state determination device 4 mounted on the legs of the trainee U. In FIG. 5, for convenience of explanation, the components other than the walking assist device 2 and the walking state determination device 4 in the walking training system 1 are omitted.

The walking state determination device 4 is configured to be attachable to a predetermined portion of the lower limbs of the trainee U. In the example of FIG. 5, the walking state determination device 4 is attached to the ankle of the right leg U2 opposite to the left leg U1 to which the walking assist device 2 is attached.

Specifically, the walking state determination device 4 includes an ultrasonic sensor 4a, a calculation unit 4b, and a fixing unit 4c. The ultrasonic sensor 4a is attached to, for example, the ankle of the right leg U2 of the trainee U, and detects the position (distance L and angle θ) of the left leg U1 from the right leg U2.

The ultrasonic sensor 4a transmits ultrasonic waves from the transmitter to the periphery of the left leg U1 which is an object, and receives the reflected waves by the receiver. Then, the ultrasonic sensor 4a is attached to the distance and angle of the object from the ultrasonic sensor 4a, that is, the ultrasonic sensor 4a, based on the intensity of the reflected wave and the time required for transmission and reception of the ultrasonic wave. The distance L and the angle θ of the left leg U1 to which the walking assist device 2 is attached are calculated from the right leg U2.

The fixing portion 4c is for fixing the ultrasonic sensor 4a to a predetermined portion of the trainee U, and is a band such as a medical supporter.

The calculation unit 4b determines the walking state of the trainee U based on the detection result of the ultrasonic sensor 4a. The arithmetic unit 4b stores, for example, a CPU (Central Processing Unit) that performs arithmetic processing, control processing, etc., a ROM (Read Only Memory) that stores an arithmetic program executed by the CPU, a control program, and various data. The hardware is composed mainly of a microcomputer including a RAM (Random Access Memory), an interface unit (I / F) for inputting / outputting signals to and from the outside, and the like. The CPU, ROM, RAM, and interface unit are connected to each other via a data bus or the like.

≪Explanation of walking condition judgment method≫
Subsequently, a method of determining the walking state of the trainee U will be described.
In the walking training system 1, it is necessary to determine the walking state of the trainee U during training in order to provide appropriate assistance according to the walking state of the trainer U. Here, in the walking motion, when the affected leg to which the walking assist device 2 is attached is in the stance state, the load applied to the affected leg is relatively large, and when the affected leg is in the swing state, the load is relatively large. , The load on the affected leg is relatively small. Therefore, the walking assist device 2 relatively increases the resistance value of the damper 22 provided in the walking assist device 2 at least during the period in which the affected leg to which the walking assist device 2 is attached is in a stance state. It is necessary to assist the trainer U in walking.

FIG. 6 is a diagram showing the relationship between the walking state of the trainee U and the position of the other leg from one leg to which the ultrasonic sensor 4a is attached. Further, FIG. 7 is a diagram showing the distribution of the signal intensity dB acquired by the ultrasonic sensor 4a in each walking state of the trainee U. In the examples of FIGS. 6 and 7, the walking assist device 2 is attached to the left leg U1 which is the affected leg, and the walking state determination device 4 is attached to the ankle of the right leg U2. Unless otherwise specified, the walking state described below indicates the walking state of the left leg U1 which is the affected leg.

As shown in FIG. 6, the walking motion of the trainee U is divided into eight walking states T1 to T8 per walking cycle. The walking state T1 represents a state of initial contact. The walking state T2 represents a state of a load response period (Loading Response). The walking state T3 represents a state in the middle stage of stance (Mid State). The walking state T4 represents a state of the terminal stage (Terminal Stance). The walking state T5 represents a state of the pre-swing period (Pre-Swing). The walking state T6 represents the state of the initial swing. The walking state T7 represents the state of the mid-swinging leg (Mid Swing). The walking state T8 represents a state of the end of the swing leg (Terminal Stance).

The period from the walking state T1 to the walking state T2 is collectively referred to as the early stance phase, the period from the walking state T3 to the walking state T4 is collectively referred to as the late stance phase, and the period from the walking state T5 to the walking state T6 is summarized. The period from the walking state T7 to the walking state T8 is collectively referred to as the early swing leg.

As shown in FIGS. 6 and 7, at t11 at the start of the early stance phase, the left leg U1 seen from the right leg U2 is located forward in the traveling direction. That is, the angle θ of the left leg U1 as seen from the right leg U2 shows a positive value when the direction perpendicular to the traveling direction is 0 degrees. Further, at this time, the distance L from the right leg U2 to the left leg U1 is relatively long. After that, as the walking progresses, the left leg U1 approaches the right leg U2, so that the angle θ approaches 0 degrees from the positive value and the distance L becomes shorter. Therefore, assuming that the amount of change in the angle θ is Δθ and the amount of change in the distance L is ΔL, the calculation unit 4b of the walking state determination device 4 determines that Δθ <0, ΔL <0 is detected by the ultrasonic sensor 4a. It is determined that the walking state of the left leg U1, which is the affected leg, is the early stage of stance.

Further, at the start t12 of the latter stage of stance, the right leg U2 and the left leg U1 are in a state of being aligned perpendicular to the traveling direction. That is, the angle θ of the left leg U1 as seen from the right leg U2 indicates 0 degrees. Further, at this time, the distance L from the right leg U2 to the left leg U1 is relatively short. After that, as the walking progresses, the left leg U1 seen from the right leg U2 moves away from the rear in the traveling direction, so that the angle θ becomes a negative value from 0 degrees and the distance L becomes longer. Therefore, when the calculation unit 4b of the walking state determination device 4 detects Δθ <0, ΔL> 0 by the ultrasonic sensor 4a, the calculation unit 4b determines that the walking state of the left leg U1, which is the affected leg, is in the late stance phase. ..

At t13 at the start of the first half of the swing leg, the left leg U1 seen from the right leg U2 is located behind in the traveling direction. That is, the angle θ of the left leg U1 as seen from the right leg U2 shows a negative value when the direction perpendicular to the traveling direction is 0 degrees. Further, at this time, the distance L from the right leg U2 to the left leg U1 is relatively long. After that, as the walking progresses, the left leg U1 approaches the right leg U2, so that the angle θ approaches 0 degrees from a negative value and the distance L becomes shorter. Therefore, when the calculation unit 4b of the walking state determination device 4 detects Δθ> 0 and ΔL <0 by the ultrasonic sensor 4a, the calculation unit 4b determines that the walking state of the left leg U1 which is the affected leg is the early swinging leg. To do.

At the start t14 of the late swing leg, the right leg U2 and the left leg U1 are aligned perpendicular to the traveling direction. That is, the angle θ of the left leg U1 as seen from the right leg U2 indicates 0 degrees. Further, at this time, the distance L from the right leg U2 to the left leg U1 is relatively short. After that, as the walking progresses, the left leg U1 seen from the right leg U2 moves away from the front in the traveling direction, so that the angle θ becomes a positive value from 0 degrees and the distance L becomes longer. Therefore, when the calculation unit 4b of the walking state determination device 4 detects Δθ> 0 and ΔL> 0 by the ultrasonic sensor 4a, the calculation unit 4b determines that the walking state of the left leg U1 which is the affected leg is the late swing leg. To do.

Since t15 at the end of the late swing leg is the same as t11 at the start of the early stance phase, the description thereof will be omitted.

≪Flowchart≫
Subsequently, the flow of the method of determining the walking state of the trainee U will be described with reference to FIG. FIG. 8 is a flowchart showing a walking state determination method by the walking state determination device 4. In the example of FIG. 8, the walking assist device 2 is attached to the left leg U1 which is the affected leg, and the walking state determination device 4 is attached to the ankle of the right leg U2, as in the case of FIGS. 6 and 7. ..

First, the ultrasonic sensor 4a detects the position (angle θ and distance L) of the left leg U1 from the right leg U2 (step S101).

When the change amount Δθ> 0 of the angle θ and the change amount ΔL> 0 of the distance L (YES in step S102 → YES in step S103), the calculation unit 4b of the walking state determination device 4 is the left leg which is the affected leg. It is determined that the walking state of U1 is the late swing leg (step S104).

When the change amount Δθ> 0 of the angle θ and the change amount ΔL <0 of the distance L (YES in step S102 → NO in step S103), the calculation unit 4b of the walking state determination device 4 is the left leg which is the affected leg. It is determined that the walking state of U1 is the early swing leg (step S105).

When the change amount Δθ <0 of the angle θ and the change amount ΔL> 0 of the distance L (NO in step S102 → YES in step S106 → YES in step S107), the calculation unit 4b of the walking state determination device 4 suffers from the disease. It is determined that the walking state of the left leg U1, which is a leg, is in the late stage of stance (step S108).

When the change amount Δθ <0 of the angle θ and the change amount ΔL <0 of the distance L (NO in step S102 → YES in step S106 → NO in step S107), the calculation unit 4b of the walking state determination device 4 suffers from the disease. It is determined that the walking state of the left leg U1 which is a leg is the early stage of stance (step S109).

When the amount of change of the angle θ is Δθ = 0 (NO in step S102 → NO in step S106), the calculation unit 4b of the walking state determination device 4 determines that the walking state is in the stopped state (step S110).

After that, when the determination of the walking state is continued (YES in step S111), the process returns to the process of step S101, and when the determination of the walking state is not continued (NO in step S111), the process ends.

In the walking assist device 2 attached to the left leg U1 which is the affected leg, the control unit 28 determines that the left leg U1 is in a stance state by the walking state determination device 4 (more preferably, the left leg U1 is in a stance state). (When it is detected that the swing state has been switched to the stance state), the resistance value of the damper 22 of the walking assist device 2 is relatively increased. As a result, the walking assist device 2 can assist the trainer U in walking during the stance period in which a large load is applied to the left leg U1 which is the affected leg.

On the other hand, in the walking assist device 2, when the walking state determination device 4 determines that the left leg U1 is in the swing state (more preferably, the left leg U1 is switched from the standing state to the swing state). When it is detected), the resistance value of the damper 22 of the walking assist device 2 is relatively reduced. As a result, the walking assist device 2 reduces the walking assistance of the trainee U during the swing period in which the load applied to the left leg U1, which is the affected leg, is reduced.

In the examples of FIGS. 6, 7 and 8, the case where the walking assist device 2 is attached to the left leg U1 which is the affected leg and the walking state determination device 4 is attached to the ankle of the right leg U2 will be described as an example. However, it is not limited to this. For example, when the right leg U2 is the affected leg, the walking assist device 2 may be attached to the right leg U2 which is the affected leg, and the walking state determination device 4 may be attached to the ankle of the left leg U1.

As described above, the walking state determination device 4 according to the present embodiment is configured to be easily attached to any part of the lower limbs, unlike the case of a pressure sensor or the like that needs to be attached to the sole of the foot. Further, since the walking state determination device 4 according to the present embodiment is configured to be easily attached to an arbitrary portion of the lower limbs, it is possible to prevent the wiring structure from becoming complicated.

Further, since the walking state determination device 4 according to the present embodiment determines the walking state of the other leg based on the position of the other leg from one leg and its change, the walking state of the other leg is determined to be on the ground. Even if the walking is abnormal such that the distance between the legs and the pressure received from the ground on the legs becomes unstable, it is possible to determine whether the walking is in a standing state or a swinging state. ..

<Embodiment 2>
The walking state determination device 5 according to the second embodiment further includes a second ultrasonic sensor 4d as compared with the case of the walking state determination device 4. The second ultrasonic sensor 4d is attached to, for example, the ankle of the affected leg and detects the height of the affected leg from the ground. The calculation unit 4b determines the walking state of the affected leg based on not only the detection result by the ultrasonic sensor 4a but also the detection result by the ultrasonic sensor 4d. Since the other configurations of the walking state determination device 5 are the same as those of the walking state determination device 4, the description thereof will be omitted.

FIG. 9 is a diagram showing the relationship between the walking state of the trainee U and the position (height) of the leg to which the second ultrasonic sensor 4d of the walking state determination device 5 is attached from the ground. In the example of FIG. 9, a second ultrasonic sensor 4d is attached to the ankle of the left leg U1 which is the affected leg together with the walking assist device 2. Unless otherwise specified, the walking state described below indicates the walking state of the left leg U1 which is the affected leg.

As shown in FIG. 9, in the early stance phase and the late stance phase, the height H of the left leg U1 from the ground shows a value of 0 (assuming that the amount of change in height H is ΔH, ΔH = 0). On the other hand, in the early stage of the swing leg, the height H of the left leg U1 from the ground gradually increases (ΔH> 0), and in the latter stage of the swing leg, the height H of the left leg U1 from the ground gradually decreases (). ΔH <0). The calculation unit 4b of the walking state determination device 4 determines the walking state of the left leg U1 which is the affected leg based on ΔH in addition to Δθ and ΔL.

As described above, the walking state determination device 5 according to the present embodiment can exert the same effect as the case of the walking state determination device 4. Further, the walking state determination device 5 determines the walking state of the affected leg based on ΔH detected by the ultrasonic sensor 4d in addition to Δθ and ΔL detected by the ultrasonic sensor 4a. As a result, the walking state determination device 5 can more accurately determine the walking state of the affected leg.

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit.

For example, in the first and second embodiments, the case where an ultrasonic sensor is used as the sensors 4a and 4d has been described as an example, but the present invention is not limited to this, and other types of sensors capable of realizing the same function are used. May be done. For example, the sensors 4a and 4d may be sensors capable of wireless communication. In this case, the sensor 4a detects Δθ and ΔL according to the radio communication strength, and the sensor 4d detects ΔH according to the radio communication strength.

Further, in the first and second embodiments, the case where the walking state determination devices 4 and 5 are applied to the walking assist device 2 incorporated in the walking training system 1 has been described, but the present invention is not limited to this. As a matter of course, each walking state determination device 4 and 5 may be applied to a single walking assist device 2.

1 Walking training system 2 Walking assist device 3 Training device 4 Walking state judgment device 4a Ultrasonic sensor 4b Calculation unit 4c Fixed part 4d Second ultrasonic sensor 5 Walking state judgment device 21 Supporter 21a Surface fastener 21b Fixed band 22 Damper 23 Top Thigh frame 24 Lower leg frame 25 Ankle foot equipment 25a Foot flat frame 28 Control unit 31 Tread mill 32 Frame body 35 Control device 36 Display unit 311 Belt conveyor FT Foot flat LL Lower leg U Trainer U1 Left leg U2 Right leg UL Upper leg

Claims (1)

It is a walking state determination device that determines the walking state of a person.
An ultrasonic sensor attached to a predetermined part of one of the lower limbs of the person and detecting the position of the other of the lower limbs from one of the lower limbs and its change thereof.
An arithmetic unit that determines the walking state of the person based on the detection result of the ultrasonic sensor, and
A walking state determination device equipped with.

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