Walking aids

Abstract

To provide a walking assist machine having a small-size, light-weight and simple structure, assisting spontaneous walking by causing a user to sense a movement direction and movement timing and instructing the movement, and allowing the user to walk relatively long distances with a near-normal gait cycle without feeling fatigue even after long-term use in the machine for supporting foot movements along normal walking motion when elderly people. etc. capable of walking by their own, spontaneously walk for promoting exercise for the purpose of health maintenance.SOLUTION: A walking assist machine 1 includes directional vibrators 11a and 11b configured to come into contact with at least one of an instep 21 and a foot sole 24, and a vibration controller for causing the directional vibrators 11a and 11b to generate vibrations with asymmetrical waveforms in synchronization with plantar flexion and dorsiflexion motion of a foot to be performed at a prescribed phase of the walking cycle, and causing the foot to move to sense movement direction and movement timing and to instruct the plantar flexion and dorsiflexion motion of the foot.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a walking aid for assisting walking movements. [Background technology]

[0002] The basic walking movement involves stepping out with the raised leg and landing on the heel (heel strike), landing on the heel and toes (loading response), shifting the weight of the upper body forward and standing with the leg straight (mid stance), lifting the heel and shifting the weight to the toes (terminal stance), kicking off the ground and beginning to lift the toes (pre-swing), lifting the toes and raising the foot (toe off), stepping out (mid swing), and moving the foot forward so that the heel touches the ground (terminal swing).This walking cycle is repeated alternately with the left and right legs.

[0003] During this walking motion, even healthy young people find it difficult to lift their toes and are likely to stumble when they get tired, but elderly people are even more likely to have an imperfect walking motion. Moreover, such elderly people may not be able to control the direction and timing of their toe and heel movements even for just a few steps, and they may find it difficult to walk relatively long distances with a gait cycle that is close to normal.

[0004] BACKGROUND ART Various walking support systems have been disclosed for promoting exercise for the purpose of maintaining the health of elderly people, and for supporting the walking of people with lower limb disabilities and rehabilitation patients.

[0005] For example, Patent Document 1 discloses a technology related to a walking motion assist device that assists the wearer in rotating the ankle joint. This walking motion assist device is capable of rotating coaxially with the ankle joint using a drive motor. A basic motion pattern representing the time-series changes in the ankle joint angle during a walking cycle is stored, and the basic motion pattern is modified based on input from an operator to generate a modified motion pattern. A control device controls the drive of the drive motor based on the modified motion pattern. Such walking motion assist devices contribute to supporting the walking of many rehabilitation patients, but they tend to be heavy due to the use of a drive source, and are not suitable for promoting exercise for elderly people or frail people who do not require assistance from a large torque.

[0006] Furthermore, Patent Document 2 discloses a functional electrical stimulation walking assist device in which a signal is sent wirelessly from a pressure switch attached to the insole of the shoe of the healthy leg, and the walking assist device main body (treatment device main body) predicts the timing of the movement of the affected leg from the movement of the healthy leg and applies functional electrical stimulation pulses with an appropriate output envelope pattern to the affected leg at the appropriate timing. This functional electrical stimulation walking assist device can be made lighter than those that use a motor as a drive source, but because it applies electrical stimulation to muscles that are suffering from motor paralysis, it cannot be said to be suitable for promoting movement. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2017-217039 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-313555 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide a walking aid that supports the movement of the feet in accordance with normal walking motion when elderly people and others walk spontaneously, in order to enable them to walk on their own and promote exercise aimed at maintaining their health. The walking aid is small, lightweight, and has a simple structure, and it assists spontaneous walking by sensing and indicating movement orientation and movement timing, and does not tire even when used for a long period of time, allowing people to walk relatively long distances with a walking cycle close to normal. [Means for solving the problem]

[0009] The walking assist device achieved in order to achieve the above object is characterized by having a directional vibrator configured to come into contact with at least one of the instep and sole of the foot, and a vibration controller that causes the directional vibrator to generate vibrations with asymmetric waveforms in synchronization with the plantar flexion and dorsiflexion movements of the foot that occur at a predetermined phase of the walking cycle, and that causes the foot to sense the movement direction and movement timing and instructs the plantar flexion and dorsiflexion movements of the foot.

[0010] In this walking assist device, the vibration controller may control and generate the vibration of the asymmetric waveform based on a program created in advance to achieve a desired walking movement.

[0011] In this walking aid, the walking aid may further have a sensor for detecting a predetermined phase that is the timing of plantar flexion and dorsiflexion of the foot during a walking cycle, and the vibration controller may control the vibration of the asymmetric waveform based on the phase obtained using the sensor.

[0012] In this walking assist device, the sensor is, for example, one of a pressure sensor that detects the pressure state of the sole of the foot during the walking cycle, an angle sensor that detects the angle of the foot, or an acceleration sensor that detects the acceleration of the foot.

[0013] In this walking aid device, it is preferable that the sensor is a pressure sensor, the pressure sensors are configured in pairs on the heel side and the toe side of the sole of the foot, and the vibration controller controls the asymmetric waveform vibration based on the pressure state on both the heel side and the toe side.

[0014] In this walking aid, it is preferable that a plurality of directional vibrators are configured to contact the top and bottom of the foot, respectively, and that the vibration controller controls the asymmetric waveform vibration of each directional vibrator so that the plurality of directional vibrators are synchronized to allow the foot to sense the direction and timing of movement.

[0015] In this walking assist device, the vibration of the asymmetric waveform may be controlled by the vibration controller so that there are more waveforms in the same direction as the foot movement direction during plantar flexion or dorsiflexion of the foot and fewer waveforms in the opposite direction to the foot movement direction.

[0016] In this walking assist device, it is preferable that the waveform in the same direction as the foot movement direction and the waveform in the opposite direction to the foot movement direction be controlled by the vibration controller so that they have equal waveform strengths.

[0017] In this walking assist device, the vibration controller may provide the directional vibrator with an asymmetric vibration generating signal generated by inverting a sine wave waveform, thereby causing the directional vibrator to generate vibrations with an asymmetric waveform.

[0018] Footwear made to achieve the above object is characterized in that the walking aid is attached to the footwear. [Effects of the Invention]

[0019] The walking aid of the present invention does not directly operate the muscles or joints of the user wearing it, particularly the elderly, or directly assist the muscles or joints with an assisting force, but rather uses directional vibrations to indicate the movement direction and movement timing so that the legs, particularly the feet, can move spontaneously in the same way as normal, thereby assisting the muscles and joints to move appropriately. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a partial cross-sectional view showing an example of a walking assist device to which the present invention is applied. [Figure 2] 1 is a schematic diagram of an asymmetric waveform in a walking assist device to which the present invention is applied. [Figure 3] 10A and 10B are diagrams showing the results of a study on the optimum mounting position and optimum frequency of a directional vibrator used in a walking aid to which the present invention is applied. [Figure 4] 1 is a schematic diagram showing a specific embodiment of a walking assist device to which the present invention is applied. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments for carrying out the present invention will be described in detail, but the scope of the present invention is not limited to these embodiments.

[0022] A walking aid device 1 of the present invention will be described with reference to FIG. 1 , which shows an outline of one embodiment of the device. As shown in FIG. 1 , the walking aid device 1 is a piece of footwear 10 that includes directional vibrators 11a and 11b attached to the instep 21 and sole 24 of a foot 20 so as to contact the instep 21 and sole 24, a vibration controller 31 connected to the directional vibrators 11a and 11b and controlling the generation and stopping of the directional vibrations, and pressure sensors 12a and 12b that detect loads on the heel 23 and toe 22 sides of the sole 24, respectively. In this embodiment, a sensor insole 16 for accommodating the pressure sensor and a vibrator insole 15 for accommodating the directional vibrator are sequentially provided on a footwear sole 17, which serves as the bottom of the shoe. While the directional vibrators 11a and 11b are preferably attached to the instep 21 and sole 24, respectively, either one may be used.

[0023] The directional vibrator 11a on the instep 21 side is arranged so as to contact the instep 21, preferably around the base of the big toe, and is fixed to a vibrator fixing belt 14 connected to the footwear sole 17. The directional vibrator 11b on the sole 24 side is arranged so as to contact the sole 24, preferably around the ball of the foot, and is housed in a hole opened in the vibrator insole 15 near the part corresponding to the ball of the foot.

[0024] Pressure sensors 12a and 12b are housed in holes bored in sensor insole 16 near the heel and ball of the foot, while making contact with vibrator insole 15. While pressure sensor 12b is in contact with directional vibrator 11b in FIG. 1, this configuration is also acceptable. Sensor insole 16 is sandwiched between vibrator insole 15 and footwear sole 17 and fixed by adhesive or heat fusion to prevent separation. Vibrator insole 15, sensor insole 16, and footwear sole 17 are made of common rubber sponge insoles. Vibrator fixing belt 14 and footwear belts 13a and 13b secure sandals to foot 20 to prevent them from slipping off, but the footwear may also be shoes.

[0025] Wires 12c and 12d that transmit pressure detection signals from pressure sensors 12a and 12b are connected to vibration controller 31. Vibration controller 31 detects pressure on the heel 23 side and the toe 22 side using pressure sensors 12a and 12b, and generates a vibration generation signal based on the detected pressure. Vibration controller 31 has a control circuit that generates a vibration generation signal for applying vibrations with asymmetric waveforms to directional vibrators 11a and 11b. Wires 11c and 11d that transmit the vibration generation signal from vibration controller 31 are connected to directional vibrators 11a and 11b.

[0026] Vibration controller 31 detects pressure on the heel 23 side and the toe 22 side using pressure sensors 12a and 12b, respectively, and generates a vibration generation signal based on the detected pressure. Wiring 11c and 11d, which transmit the vibration generation signal from vibration controller 31, are connected to directional vibrators 11a and 11b. Specifically, vibration controller 31 has a control circuit, and wiring 12c and 12d, which transmit the pressure detection signals from pressure sensors 12a and 12b, are connected to the control circuit of vibration controller 31. Based on these signals, the control circuit of vibration controller 31 generates a vibration generation signal for applying asymmetric waveform vibrations to directional vibrators 11a and 11b.

[0027] In this embodiment, the vibration controller 31 is housed in a vibration controller cover 32. The vibration controller cover 32 has the directional vibrators 11a and 11b and a power supply (not shown) that drives the vibration controller 31. A vibration controller belt 33 to which the vibration controller cover 32 is fixed is attached to the ankle. Instead of attaching it to the ankle, the vibration controller 31 and the power supply may be housed in the footwear sole 17, or may be attached to the foot or leg, waist, or upper body. The footwear sole 17 may be provided with a heel, and the vibration controller 31 may be housed in the heel.

[0028] Here, we will explain the directional vibrator that instructs the foot in a movement direction at a predetermined movement timing. The directional vibrators 11a and 11b can be, for example, vibration speakers such as voice coil actuators. A voice coil actuator is composed of a spring-driven permanent magnet and a coil. When a current is passed through the coil, a magnetic field is generated, causing the permanent magnet to move. When a voltage change corresponding to a periodic signal is applied to the coil, the current flowing through the coil changes in a manner corresponding to the periodic signal, which causes the magnetic field to change over time, and the attraction and repulsion of the permanent magnet generates vibration.

[0029] At this time, by adjusting the current flowing through the coil (voltage applied to the coil), it is possible to generate a positive asymmetric waveform vibration where the waveform is biased in the positive direction, or a negative asymmetric waveform vibration where the waveform is biased in the negative direction, as shown in Figure 2(a). A specific adjustment method will be explained with reference to Figure 2(b). Figure 2(b) is an example of generating a positive asymmetric waveform vibration as shown in Figure 2(a), and is a diagram showing the correlation between the elapsed time and the voltage applied to the coil for a series of repeated cycles (one period) of the asymmetric waveform. The reference voltage V according to the applied voltage basic (For example, the average of the applied maximum voltage and the applied minimum voltage, or the voltage at the inflection point of a positive asymmetric waveform or a negative asymmetric waveform) is applied to the coil of the vibration speaker to increase the reference voltage V basic By applying a voltage below 1 V to the coil of the vibration speaker, the diaphragm of the vibration speaker can be displaced in the negative direction. As shown in Figure 2(b), by changing the voltage over time so that the voltage vibrating in the positive direction is increased and the voltage vibrating in the negative direction is decreased, it is possible to obtain vibration with a positive asymmetric waveform as shown in Figure 2(a). Note that in Figure 2(b), the voltage is increased and decreased in stages using Pulse Code Modulation (PCM), but it can also be increased and decreased continuously using an analog method (not shown).

[0030] It is known that using a vibration speaker that vibrates with an asymmetric waveform allows the wearer to perceive a force being pulled or pushed in one direction (Tanabe et al., "Properties of Proprioceptive Sensation with a Vibration Speaker-type Non-grounded Haptic Interface," IEEE HAPTICS SYMPOSIUM '16 APRIL 8-11, 2016). In this embodiment, vibration speakers are used as the directional vibrators 11a and 11b, and by applying vibrations with an asymmetric waveform, the wearer can feel a sensation of being pulled or pushed in a predetermined direction, thereby instructing the direction of movement. The voltage applied to the directional vibrators 11a and 11b can be appropriately amplified by an amplifier, allowing the vibration intensity (waveform size) to be changed according to the wearer's sensitivity.

[0031] Next, an experiment to confirm the effect of the vibration speaker in this embodiment will be described. Four adult male subjects, aged 22–25 years, 167–179 cm tall, and weighing 52–72 kg, wore sandals equipped with directional vibrators (vibration speakers) positioned on the top and bottom of the feet toward the toes. We investigated the effect of asymmetric vibrations on the perception of movement direction when the vibration speakers were applied. The asymmetric vibrations were positive-asymmetric, as shown in Figure 3(c), obtained by inverting a sine wave. One cycle consisted of two to five positive-going time domains and one negative-going time domain. A positive-negative symmetrical waveform (a standard sine wave) was also used as a comparison. The subjects were given a 100 Hz vibration, and the subjects were given a five-point rating. A rating of 4 was given if the subjects clearly perceived the vibration speaker's directionality (pulling or pushing force in one direction), a rating of 3 if the directionality was fully perceived, a rating of 2 if the directionality was somewhat perceived, a rating of 1 if the directionality was barely perceived, and a rating of 0 if the directionality was completely unperceivable. Table 1 shows the results.

[0032] [Table 1]

[0033] As is clear from Table 1, when the ratio of the number of positive and negative time domains was 1:1 (sine wave), which was used as a comparative example, no directivity was perceived, whereas it was confirmed that by applying vibration with an asymmetric waveform to the vibration speaker, directivity could be perceived. In particular, when applying vibration with an asymmetric waveform with a ratio of the number of positive and negative time domains of 3:1, the directivity perception scores of all subjects were significantly improved compared to when the ratio was 2:1, 4:1, or 5:1.

[0034] Furthermore, in the inventors' research experiments, it was found that, as described above, using an asymmetric waveform vibration that combines multiple positive-going waveforms and one negative-going waveform makes it easier to feel a sense of being pushed in the positive direction, whereas using a positive-asymmetric waveform vibration that consists only of positive-going waveforms makes it difficult to feel a sense of being pushed in the positive direction. Furthermore, as shown in Figure 2(d), when the waveform strength in the positive direction and the waveform strength in the negative direction are unequal, it is harder to feel a sense of being pushed or pulled in the positive direction than when they are equal. For this reason, it is preferable to use a positive-asymmetric waveform vibration that has equal waveform strengths in the positive direction and the negative direction.

[0035] 2(a) to 2(c) show an example of an asymmetric waveform vibration obtained by inverting a sine wave, but as shown in FIG. 2(e), an asymmetric waveform vibration consisting of a triangular wave, a square wave, or a sawtooth wave may also be used. However, the asymmetric waveform vibration obtained by inverting the sine wave waveform shown in FIG. 2(a) to 2(c) is particularly preferable because it is the easiest to detect. Among these asymmetric waveforms, a sine wave allows for very clear direction detection, while a square wave allows for some degree of detection, so a sine wave or a square wave is preferable, and a sine wave is even more preferable.

[0036] Next, directional vibrators (vibration speakers) were attached to the first metatarsal bone on the instep, the arch, and the heel, and secured with supports. We examined the effect of varying the frequency of the vibration speakers at each fixed position on directional perception. Two types of asymmetric waveform vibrations were used: a positive asymmetric waveform with a positive-to-negative time domain ratio of 3:1 and a negative asymmetric waveform with a positive-to-negative time domain ratio of 1:3. Vibration frequencies were applied in 10-Hz increments from 20 to 110 Hz, and three subjects rated the directional perception on a five-point scale (0 to 4), as in the previous study. Figure 3 shows the evaluation results. The vibration speakers were secured so that positive asymmetric waveform vibrations resulted in an upward force, and negative asymmetric waveform vibrations resulted in a downward force. The perception rating (labeled "Perception Rate") was calculated as the average of the three subjects.

[0037] As can be seen from the Perception Rate in Figure 3, the instep (labeled "Instep") was able to sensitively and accurately perceive both positive and negative asymmetric waveform vibrations at 30-50 Hz (labeled "Suitable Range"), and downward (labeled "Down") asymmetric waveform vibrations were more pronounced than upward (labeled "Up"). The arch (labeled "Arch") was able to perceive vibrations, but had difficulty perceiving the direction of either positive or negative asymmetric waveform vibrations. On the other hand, the ball of the foot (labeled "Ball") was able to sensitively and accurately perceive both positive and negative asymmetric waveform vibrations at 30-50 Hz, and upward asymmetric waveform vibrations were more pronounced than downward. Both the instep and ball of the foot were able to perceive both positive and negative asymmetric waveform vibrations at 80-110 Hz, but were unable to distinguish their direction (labeled "Can't distinguish"). From this, it was found that when instructing the direction of foot movement during walking, it is desirable to place a directional vibrator on the instep or near the ball of the foot on the sole, that it is desirable to use vibrations with an asymmetric waveform that can be sensed as a pushing direction rather than a pulling direction on both the instep and near the ball of the foot, and that it is desirable to use a frequency of 30 to 50 Hz.

[0038] As can be seen from the above experimental results, the directional vibrators 11a and 11b can make the foot 20 sense the movement direction and movement timing of the foot that should be moved in accordance with the plantar flexion and dorsiflexion movements of the foot.

[0039] The walking assist device 1 shown in FIG. 1 uses a vibration controller 31 to control the asymmetric waveform vibrations of the directional vibrators 11a and 11b so that the movement directions and movement timings of the plantar flexion movement assistance and the dorsiflexion movement assistance are synchronized with the plantar flexion movement and dorsiflexion movement of the foot 20.

[0040] Specifically, during plantar flexion, directional vibrators 11a and 11b must be controlled so that the direction of the movement, which is the pushing direction, that is, the downward direction, is sensed in order to push off by pushing the toe of foot 20 against the ground while lifting heel 23 off the ground. For this reason, directional vibrator 11a is controlled by vibration controller 31 to generate vibrations with an asymmetric waveform that senses that instep 21 is being pushed, and directional vibrator 11b to generate vibrations with an asymmetric waveform that senses that sole 24 is being pulled.

[0041] On the other hand, during dorsiflexion, it is necessary to control directional vibrators 11a and 11b so that the movement direction, which is the direction of lifting, i.e., the upward direction, is sensed in order to lift toes 22 above heel 23. For this reason, directional vibrator 11a is controlled by the vibration controller to generate vibrations with an asymmetric waveform that senses that sole 24 is being pressed, and directional vibrator 11b to generate vibrations with an asymmetric waveform that senses that instep 21 is being pulled.

[0042] In this walking aid, a pair of directional vibrators 11a and 11b are attached to the instep 21 and sole 24 of each foot, and they synchronously indicate the direction of hypoflexion or dorsiflexion. As explained in the experiment shown in Figure 4, one directional vibrator can sense the upward and downward directions, so it is possible to sense the direction of hypoflexion and dorsiflexion using only one of the directional vibrators 11a and 11b. However, using a pair of directional vibrators 11a and 11b allows vibrations in the pushing direction, which are highly sensitive, to act in both the plantarflexion and dorsiflexion directions, which is a more preferable embodiment.

[0043] Directional vibrators 11a and 11b have better sensitivity when they direct directional vibrations of asymmetric waveforms at bones and sense bone vibrations rather than at muscles. Therefore, directional vibrator 11a is preferably directed at the first proximal phalanx of the big toe and / or the first metatarsal, among the phalanges, on instep 21. Meanwhile, directional vibrator 11b is preferably directed at the first proximal phalanx and / or the first metatarsal, particularly the sesamoid bone of the first metatarsal, on sole 24.

[0044] Directional vibrators 11a and 11b can be, for example, vibration speakers of about 5 cm each, and can use frequencies in the range of 20 to 110 Hz. However, if the frequency is too low, it is difficult to feel the vibration, and if the frequency is too high, it is difficult to feel the directionality of the vibration. Therefore, when instructing the foot to move in a certain direction, it is preferable to use a frequency of 30 to 50 Hz, as shown in the experimental study in Figure 3.

[0045] Pressure sensors 12a and 12b can be pressure-sensitive conductive rubber pressure sensors whose resistance decreases when pressed. This is achieved by incorporating conductive material particles into insulating rubber, which adhere to the surface when pressure is applied, causing the resistance to decrease in response to the pressure. Pressure can be detected by applying a voltage (e.g., 5 V) to a circuit in which a pressure-sensitive conductive rubber pressure sensor whose resistance decreases when pressed and a constant resistor are connected in series, and measuring the voltage (e.g., 0 to 5 V) across the constant resistor. The pressure sensor may also be a so-called capacitance pressure sensor, which detects pressure through changes in capacitance caused by applied pressure.

[0046] The vibration controller 31 includes a control circuit that generates a vibration generating signal that applies an asymmetric waveform vibration to the directional vibrators 11a and 11b, and a comparison circuit that determines whether pressure is being applied (high or low pressure) based on the pressure detection signals sent from the pressure sensors 12a and 12b. The vibration controller 31 also includes a processor that operates according to a predetermined program to determine whether plantar flexion assistance or dorsiflexion assistance is required based on the pressure applied to the pressure sensors 12a and 12b, and to generate a vibration generating signal at the desired operation timing and instruct the directional vibrators 11a and 11b. These functions are not limited to the above examples and can be realized using any known electronic circuit or processor, as appropriate.

[0047] Next, the gait cycle of both legs and plantar flexion and dorsiflexion assistance will be described with reference to Figures 4(a) to 4(c). Figure 4(a) shows a gait cycle, with one step each for the left and right feet, ignoring the movement of the right foot. A gait cycle can be divided into two phases: a stance phase, in which the foot is in contact with the ground and bearing weight, and a swing phase, in which the foot is in the air. As shown in Figure 4(a), the stance phase can be divided into multiple phases based on walking, including the heel-strike phase, load-bearing phase, mid-stance phase, and end-stance to pre-swing phase, and the swing phase can be divided into pre-swing phase, early swing phase, and mid-swing to end-swing phase (heel-strike phase). In typical walking, plantar flexion of the foot occurs from end-stance to pre-swing phase, and dorsiflexion of the foot occurs from early swing to mid-swing phase. In Figure 4(a), the phase at heel contact at the beginning of the stance phase is represented as 0%, and the phase at heel contact at the end of the swing phase is represented as 100% (0% at heel contact in the next gait cycle).

[0048] Figure 4(b) shows the change in heel and toe load during a gait cycle as detected by pressure sensors. The horizontal axis represents the gait phase, as in Figure 4(a). The phase at heel contact at the beginning of the stance phase is 0% and the phase at heel contact at the end of the swing phase is 100% (0% at heel contact in the next gait cycle). The solid line represents the change in heel load, and the dashed line represents the change in toe load. A pressure-sensitive conductive rubber pressure sensor, whose resistance decreases with pressure, was used, as described above. The vertical axis represents the measured voltage of a constant resistance, with higher measured voltage indicating greater pressure (load). As can be seen in Figure 4(b), both the toe-side pressure sensor 12a and the heel-side pressure sensor 12b can be roughly divided into two regions: high pressure and low pressure during walking. Table 2 shows the relationship between the detected pressures of the toe-side pressure sensor 12a and the heel-side pressure sensor 12b and the gait phase during walking.

[0049] [Table 2]

[0050] Plantar flexion assistance and dorsiflexion assistance will be explained with reference to Figure 4(c). First, during the heel contact phase when the raised leg steps out and lands on the heel, pressure sensor 12a on the toe 22 side detects a low load, and pressure sensor 12b on the heel 23 side detects a high load. Thus, when there is low pressure on the toe side and pressure on the heel side, no assistance is provided for plantar flexion or dorsiflexion.

[0051] Next, from the load response period when the heel and toe land, to the mid-stance period when the upper body shifts the load forward and the legs are straightened to stand, both the pressure sensor 12a on the toe 22 side and the pressure sensor 12b on the heel 23 side detect a high load (high pressure). Even at this stage, no assistance is provided for plantar flexion or dorsiflexion.

[0052] Next, from the end of the stance phase when the heel is lifted and the weight is transferred to the toes, until the front swing phase when the toes begin to lift, pressure sensor 12a on the toe 22 side detects a high load (high pressure), and pressure sensor 12b on the heel 23 side detects a low load (low pressure). When loads are detected in this combination, in order to assist plantar flexion from the end of the stance phase to the front swing phase, adjustments are made by vibration controller 31 to apply vibrations with an asymmetric waveform to foot 20 from directional vibrators 11a and 11b in the direction of movement, i.e., downward, which is the pressing direction.

[0053] Next, from the initial swing stage when the toe is lifted and the foot is raised, to the mid-swing stage when the foot steps out, both pressure sensor 12a on the toe 22 side and pressure sensor 12b on the heel 23 side detect a low load (low pressure). When a load is detected in this combination, in order to provide dorsiflexion assistance from the initial swing stage to the mid-swing stage, directional vibrators 11a and 11b apply vibrations with an asymmetric waveform to foot 20 in the movement direction of lifting, i.e., upward, by adjustment using vibration controller 31.

[0054] Then, in the final swing phase (corresponding to the heel-contact phase of the next walking cycle) when the foot moves forward to touch the heel, pressure sensor 12a on the toe 22 side detects a low load, and pressure sensor 12b on the heel 23 side detects a high load. At this point, dorsiflexion assistance is stopped.

[0055] As explained above, the pressure sensor 12a on the toe 22 side and the pressure sensor 12b on the heel 23 side detect changes in load (pressure) corresponding to each phase of walking movement, and it is possible to appropriately assist plantar flexion and dorsiflexion of the foot based on the movement timing obtained by combining the detected pressures.

[0056] In Figures 4(a) to (c), the walking cycle of only the right leg is shown abstractly, but the left and right legs alternately repeat the process from the heel contact phase to the end of the swing phase, so plantar flexion assistance and dorsiflexion assistance are similarly performed on the left leg.

[0057] In the present embodiment, an example has been shown in which the vibration controller 31 determines the operation timing according to the pressure from the pressure sensors 12a and 12b, and controls the directional vibrators 11a and 11b to apply vibrations with asymmetric waveforms to assist the plantar flexion and dorsiflexion of the foot 20. However, it is also possible to set a time schedule in advance based on operation timing that results in an ideal walking cycle, and based on that operation timing, the vibration controller 31 controls the directional vibrators 11a and 11b to apply vibrations with asymmetric waveforms to assist the plantar flexion and dorsiflexion of the foot 20.

[0058] Furthermore, in this embodiment, pressure sensors that detect the load on the toes and heels are used as sensors for determining the walking phase, which is the timing of plantar flexion and dorsiflexion of the foot during a walking cycle, but instead of these, an angle sensor may be used to detect the angle of foot 20, and the vibration controller may control the vibration of an asymmetric waveform to synchronize with the angle. Specifically, plantar flexion assistance can be performed when an angle sensor attached to instep 21 or sole 24 indicates that the angle of foot 20 is below approximately horizontal between the end of stance and the front swing phase, and dorsiflexion assistance can be performed when an angle sensor indicates that the angle of foot 20 is returning to the horizontal direction or has returned to approximately horizontal between the beginning of swing and the middle of swing.

[0059] Furthermore, instead of pressure sensors or angle sensors, acceleration sensors may be attached near the toes or heels to determine each phase based on changes in acceleration and provide plantar flexion or dorsiflexion assistance.Other sensors may also be well-known force sensors, strain sensors, rotary encoders, or potentiometers.

[0060] In this way, various sensors detect plantar flexion and dorsiflexion of the legs, determine the phase from the information from these sensors, and apply directional vibrations from the directional vibrator according to that phase, thereby enabling assistance with walking as in normal situations to be provided naturally in accordance with the walking cycle for each actual walker and walking speed. [Industrial Applicability]

[0061] The walking aid of the present invention can be used by elderly people and others to train, rehabilitate, and prevent falls by restoring normal leg movements during spontaneous walking, and can also be used by healthy people to prevent falls and support them when fatigued, enabling them to reproduce normal walking.

[0062] This walking aid can also contribute to promoting exercise in the elderly, preventing strokes caused by blood clot formation due to lack of exercise and the resulting blockage of blood vessels in the brain. Because this walking aid is lightweight, it does not require a heavy motor to provide assistive force, so the desired timing of plantar flexion and dorsiflexion (walking phase) can be set, and the device will provide a metronome-like rhythm based on the set walking cycle, causing the legs to move accordingly, enabling it to be used to walk healthily. [Explanation of symbols]

[0063] Reference numeral 1 denotes a walking aid, 10 denotes footwear, 11a and 11b denote directional vibrators, 11c and 11d denote wiring, 12a and 12b denote pressure sensors, 12c and 12d denote wiring, 13a and 13b denote footwear belts, 14 denotes a vibrator fixing belt, 15 denotes a vibrator insole, 16 denotes a sensor insole, 17 denotes a footwear sole, 20 denotes a foot, 21 denotes an instep, 22 denotes a toe, 23 denotes a heel, 24 denotes a sole, 25 denotes an arch, 31 denotes a vibration controller, 32 denotes a vibration controller cover, 33 denotes a vibration controller belt, and 40 denotes a leg.

Claims

1. a directional vibrator configured to contact at least one of the top and bottom of the foot; a vibration controller that generates vibrations of an asymmetric waveform in the directional vibrator in synchronization with the plantar flexion and dorsiflexion movements of the foot performed at a predetermined phase of a walking cycle, and causes the foot to sense the movement direction and movement timing, thereby instructing the plantar flexion and dorsiflexion movements of the foot.

2. 2. The walking aid according to claim 1, wherein the vibration controller controls and generates the vibration of the asymmetric waveform based on a program created in advance to achieve a desired walking motion.

3. The walking aid device of claim 1, further comprising a sensor for detecting a predetermined phase that is the timing of plantar flexion and dorsiflexion movements of the foot during a walking cycle, and the vibration controller controls the vibration of the asymmetric waveform based on the phase obtained using the sensor.

4. 4. The walking aid according to claim 3, wherein the sensor is one of a pressure sensor that detects the pressure state of the sole of the foot during a walking cycle, an angle sensor that detects the angle of the foot, and an acceleration sensor that detects the acceleration of the foot.

5. The walking aid device according to claim 4, characterized in that the sensor is a pressure sensor, the pressure sensors are configured in pairs on the heel side and the toe side of the sole of the foot, and the vibration controller controls the asymmetric waveform vibration based on the pressure state on both the heel side and the toe side.

6. A walking aid device as described in any one of claims 1 to 5, characterized in that a plurality of directional vibrators are configured to contact the top and bottom of the foot, respectively, and the vibration controller controls the vibration of each directional vibrator with an asymmetric waveform so that the plurality of directional vibrators are synchronized to allow the foot to sense the direction and timing of movement.

7. A walking aid device as described in any one of claims 1 to 6, characterized in that the vibration of the asymmetric waveform is controlled by the vibration controller so that there are more waveforms in the same direction as the movement direction of the foot during plantar flexion or dorsiflexion of the foot and fewer waveforms in the opposite direction to the movement direction of the foot.

8. The walking aid device according to claim 7, characterized in that the waveform in the same direction as the foot movement direction and the waveform in the opposite direction to the foot movement direction are controlled by the vibration controller so as to have equal waveform intensities.

9. The walking aid device according to any one of claims 1 to 8, characterized in that the vibration controller provides the directional vibrator with an asymmetric vibration generating signal generated by inverting a sine wave waveform, thereby causing the directional vibrator to generate vibrations with an asymmetric waveform.

10. Footwear equipped with the walking aid according to any one of claims 1 to 9.

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