JP7614480B1 - Portable staircase ascending/descending limb strain control device and method - Google Patents

Abstract

[Problem] To provide an improved portable stair-ascending/descending limb burden control device and method that shares and relieves the burden on the lower limbs at the lower back, practically evaluates the sense of lower limb burden, and keeps the sense of lower limb burden within an appropriate range of lower limb burden.
[Solution] The waist is suspended via a rope 3 and a waist belt 1 from a handrail elevator installed on a staircase handrail 10, and when ascending a step a gripping unit 4 is placed on the staircase handrail 10 in front of the body and a brake unit 5 behind the body, the electromagnet in the brake unit 5 is stopped and the electromagnet in the gripping unit 4 is activated, and the waist is pulled upwards via the rope 3 by an electric winch 2 in the ascending direction towards the gripping unit 4, and when descending a step the gripping unit 4 is placed in front of the body and the brake unit 5 behind the body, the electromagnet is activated, and the frictional force between the friction part of the brake unit 5 and the staircase handrail 10 pulls the waist in the opposite upward direction to the descending direction where the brake unit 5 is located, relieving the load on the lower limbs by sharing it with the waist.
[Selected Figure] Figure 1

Description

The present invention relates to a portable limb load control device and method for ascending and descending stairs that shares and relieves the load on the lower limbs at the waist, practically evaluates the feeling of lower limb load, and keeps the feeling of lower limb load within an appropriate range.

In Patent Document 4, in order to search for areas with a high level of radioactive contamination, the radiation dose that would be measured if the measuring device were stationary is estimated from the time series of radiation doses and moving speed measured by the measuring device while moving, using a function fitting method, a method of determining an increasing trend in counts from the difference between two sampling seconds delayed, and a prior time series measurement of natural radiation doses.

Non-Patent Document 1 shows that elderly people who are unable to climb and descend stairs (hereinafter referred to as "ascending and descending") have weaker muscles and a stronger fear of falling than independent elderly people, which means that their range of activities is narrower and they are unable to lead an active life.

In Non-Patent Document 2, an external joint moment (hereinafter referred to as "load") acts on a joint, which is the product of an external force vector and the distance to the point of application of that vector. In addition, when movement acceleration occurs, an inertial force acts in the opposite direction.
Non-Patent Document 3 shows that in the case of squatting, within the limits where joints are not damaged, an internal joint moment (hereinafter referred to as "proof strength") is generated which is equal to the load and is the product of the muscle tension vector of the muscles and ligaments on the opposite side and the distance between the vector and the point of application.

In Non-Patent Document 4, a floor reaction force meter and an infrared reflective marker attached to the body are used to calculate the load on the lower limbs using analysis software based on the floor reaction force vector and the distance between the vector and the target joint.
In Non-Patent Document 5, the load is wavy, and the load on the joints of the lower limbs when ascending or descending is maximum when about 50% of the time required for one step during the period from when the foot touches the ground to when it leaves the ground (hereinafter referred to as the "ascending and descending cycle") has elapsed,
In Non-Patent Document 6, it is said that the body has an unconscious movement sequence of external stimuli-sensation-perception-movement (hereinafter referred to as "reflex movement function").
In Non-Patent Document 7, the reflex action time that transmits an external stimulus to a movement is 50 milliseconds for a long-latency stretch reflex with a slow response, which is shorter than the 100 to 150 milliseconds of voluntary movement that involves human consciousness and thought.
In Non-Patent Document 8, the average speed of an elderly person climbing or descending stairs is 0.21 meters per second.
The Building Standards Act requires that the tread width must be at least 26 centimeters.

In Non-Patent Document 9, when a body part is modeled as a rigid link model in which the body parts are connected by multiple joints, there is a kinetic chain function in which the movement of one part of the body affects the adjacent parts,
In Non-Patent Document 10, the balance required for ascending and descending is affected by task factors such as movement speed, personal factors such as physical function, and environmental factors such as steps (hereinafter referred to as "ascending and descending conditions");
In the non-patent document 11, when grasping a vertical handrail and standing up from a chair, the load on the elbows and the load on the knees are inversely correlated.
In addition, Non-Patent Document 12 uses a strain gauge to measure foot grip strength.

Patent Publication 2022-161457 JP2001-58758A Patent Publication No. 2013-40543 Patent 6843350 "The effects of stair climbing on motor function, activity level, and mental and physical function in community-dwelling elderly people" by Minoru Fukuo, Physical Therapy Science 29 (5) 793-797, 2014, p. 795, Table 1 "Kinematic knowledge necessary for motion analysis" by Shiji Tanino, Kansai Rigaku 2: 11-16, 2002, pp. 12-13 "Physical Therapy Considered from Biomechanics" Sato Hisatomo et al. Page 921 (Figures 4 and 5) JpnJRehabitMed2021; 50: 919-924 accessed 2023.10.20 "Biomechanics of the lower limbs during stair descent in healthy individuals" Yasumasa Tanabe et al. Physical Therapy Science 30 (2) 207-212, 2015, p. 208 "Analysis of Ascending and Descending Steps in Healthy Subjects Using Joint Moments" Hirohiko Kurogo et al. Rehabilitation Medicine 2000; 37: 389-397, p. 394 (Fig. 4), p. 396 (Fig. 5) "Interaction between human perception and movement" Satoshi Kobori, page 24, Figure 1 https://www. rikou. ryuko. ac. jp/images/journal60/RJ60-04. PDF accessed 2023.10.20 "Brain information processing that supports skillful and rapid movements - Regulation of the stretch reflex by visual body information" Sho Ito et al. NTT Technical Journal, September 2020, p. 24 "Chiba Prefecture Tsunami Evacuation Plan Guidelines (revised October 2016)" Reference: Guide to setting walking speed "The movement chain of the hip joint" Hiroshige Takeuchi, Nihon Iji Shinposha, page 31 https://jmedi.co.jp/files/item/booksPDF/978-4-7849-5907-5-para:pdf accessed 2023.10.20 "Perspectives on balance when ascending and descending stairs" by Taiki Manai, Physical Therapy 49-1, 83-91, 2022, pp. 83 and 84 (Fig. 2) "Optimal Position of Vertical Handrails and Its Biomechanical Evaluation" Aki Kawaguchi et al. Human Life Engineering Vol. 2 No. 4, October 2001, p. 36 (Figure 3) "Development of a foot grip strength measuring device using strain gauges" Shin Murata et al. Physical Therapy Science 21 (4) 363-367, 2006, p. 364

The method of suspending the body from a mobility device installed on the ceiling of a staircase in Patent Document 1 has the effect of reducing the load caused by gravity on the body (hereinafter referred to as "weight relief"); however, it requires facility modification work and the device is large, so it occupies the stairs and cannot be used on stairs shared by many people.
In addition, the method of ascending the stairs by grabbing the handle of an electric lifting device incorporated in the staircase handrail as described in Patent Documents 2 and 3 and pulling one's body against the weight of the person ascending the stairs has a load-relieving effect, but requires modification of the facility.

In the methods shown in Patent Documents 2 and 3, if the function of the arm holding the gripping bar is weakened, the grip cannot be maintained, and the tensile force of the gripping bar cannot be transmitted to the body, making it impossible to relieve the load.

In the case of experiments in Non-Patent Document 4, the load can be calculated using a floor reaction force meter and infrared reflective markers attached to the body,
In practical use, it is not possible to use a floor reaction force meter or an infrared reflective marker, and it is not possible to measure the magnitude of the external force vector and the distance from the vector to the joint, which are necessary for the load evaluation shown in Non-Patent Document 5, and therefore it is not possible to evaluate the load with this method.
A practical method is needed to evaluate the sense of burden that changes for each individual and over time, which arises from the relationship between the load that changes from moment to moment during the ascending and descending cycle (Non-Patent Document 5) and the endurance strength that changes for each individual depending on the ascending and descending conditions (Non-Patent Document 10).

When multiple people use it at the same time,
In Patent Documents 2 and 3, the tensile force of the gripping bar is uniform, so there is a possibility that some people will feel as if they are floating because the force is too strong, or conversely, that the force is too weak, resulting in insufficient load relief and insufficient strength, which can damage their joints or make it impossible for them to ascend or descend. Therefore, a control method is needed that can respond to the sense of burden that changes from person to person and over time.

The device used is a brake section 5 (Figure 2) of a scissors-shaped pressure converter 8 consisting of a brake base 6, a friction section 7 of the brake section, and two rods on which an electromagnet B24 is arranged, which cross and join at one point, and a handrail elevator 18 consisting of a scissors-shaped gripping section 4 (Figure 3) on which an electromagnet A13, a pull spring 14, a friction section 15 of the gripping section, and a contact-sensing electrical signal terminal 17 are arranged, which cross and join at one point, a waist belt 1, an electric winch 2, a rope 3, a strain gauge 16 built into the handle, an electric operation control device 9, an angle meter 25, and an accelerometer 26.

The waist is suspended from a handrail lift 18 attached to a staircase handrail 10 via a rope 3 and a waist belt 1. When ascending the stairs, a gripping part 4 is attached to the handrail 10 in front of the body and a brake part 5 is attached to the rear of the body. The electromagnet B24 of the brake part 5 is stopped and the electromagnet A13 of the gripping part 4 is operated. The waist is pulled upwards via the rope 3 by the electric winch 2 toward the gripping part 4.
When descending steps, the gripping part 4 is placed in front of the body and the brake part 5 is placed behind the body, electromagnets A13 and B24 are operated, and the frictional force between the friction part 7 of the brake part and the staircase handrail pulls the waist in the opposite upward direction to the step where the brake part 5 is located, thereby relieving the load on the lower limbs by having the waist share the load (hereinafter referred to as the "lumbar activation type load relieving process").

Non-Patent Document 6 states that the body has a reflex action function, Non-Patent Document 9 states that the body has a kinetic chain function, and Non-Patent Document 11 states that, with regard to the load, which is one of the conditions for ascending and descending that affects the sense of load, the load on the elbows and the load on the knees are inversely correlated, so it can be inferred that the empirical rule that "the sense of load on the lower limbs increases as you ascend and descend the stairs, and the strength of your hands gripping the stair railing increases" and "when you are about to fall and the load on your lower limbs suddenly changes, the grip strength of your hands gripping the stair railing suddenly increases" is a reflex action function based on the kinetic chain function of the load on the lower limbs and the grip strength of the hands. Also, Non-Patent Document 12 states that the grip strength of the feet can be measured with a strain gauge, so
A strain gauge built into the handle measures time-series voltage values representing the grip strength of the hand, and an accelerometer measures the horizontal movement speed. Referring to the method shown in Patent Document 4, a function fitting method, a method for determining the tendency for voltage to increase from the difference between two sampling seconds delayed, and a process for evaluating the lower limb burden (hereinafter referred to as a ``reflex action function-utilizing lower limb burden evaluation process'') are used to estimate a function model of the time-series burden that changes into a waveform shape based on the time-series voltage values and fluctuations of the strain gauge that correspond to a burden below the range from the upper limit of the burden where the lower limbs feel painful to the lower limit of the burden where the body feels too light and unstable (hereinafter referred to as the ``appropriate lower limb burden range'').

Using the handle-embedded strain gauge 16, the electric operation control device 9, and the angle meter 25 of the portable stair ascending/descending limb strain control device,
When ascending or descending, the user holds the handle-integrated strain gauge 16 located in front of the body with his or her hands.
In order to converge the hand grip strength measured by the strain gauge to the hand grip strength range corresponding to the appropriate lower limb strain range,
The device ascends and descends, perceives the sense of strain in the lower limbs from external stimuli, measures the resulting grip strength of the hand with a strain gauge 16 built into the handle and measures the angle of the rope 3 with a goniometer 25, calculates the maximum load and the time of appearance with the electric operation control device 9, calculates the load voltage that will bring the grip strength of the hand into an appropriate range for lower limb strain, feeds back this to the load voltage of the electric winch 2 when ascending, and to the load voltage of the electromagnet B24 of the brake unit 5 when descending, adjusts the travel time, and repeats the ascending and descending process (hereinafter referred to as the "lower limb strain feedback control process") (Figure 6).

The handrail lift of the portable staircase ascending and descending limb burden control device is of a shape and weight that can be carried by hand, and other components such as the electric winch and electric control device can be attached to a waist belt, so that the device can be used if there are staircase handrails, and no facility modification work is required.
Furthermore, when using the device, the user does not require any more foot space than is required for normal stair climbing and descending, so the user does not occupy the stairs and can share the stairs with other users of the device or non-users.

As shown in Figs. 4 and 5, which were created with reference to the kinetic chain shown in Non-Patent Document 9 and Non-Patent Documents 2 and 3, by using a lower back-activating unloading process,
When ascending or descending, the handrail pulling force moment, rope pulling force moment, floor reaction force moment, gravity moment, and accelerated inertia force moment are balanced, so when the accelerated inertia force moment is the same, if a large rope pulling force is used (Figs. 4C, 5C), the load on the lower limbs is smaller than when no rope pulling force is used (Figs. 4A, 5A) or when a small rope pulling force is used (Figs. 4B, 5B). Since the rope pulling force and the load on the lower limbs are inversely correlated, the load on the lower limbs can be relieved by sharing it with the lower back, and even people with weakened function of the lower limbs and arms can ascend or descend.

If the speed of ascent and descent is 0.21 meters per second, which is the speed of an elderly person ascending and descending stairs as described in Non-Patent Document 8, the width of the tread surface under the Building Standards Act is 26 centimeters or more (26 centimeters was used in the calculation to be on the safe side),
In Fig. 7, which was created using Figs. 4 and 5 from Non-Patent Document 5, the load on the knee joint, which is the heaviest load when ascending stairs (Fig. 7A), and the load on the ankle joint, which is the heaviest load when descending stairs (Fig. 7B), the time elapsed from when the total load on the leading and trailing legs begins to increase until it reaches its maximum (hereinafter referred to as the "time to reach maximum value") is 0.3 seconds for both ascending and descending stairs, while the reflex action time is 50 milliseconds.
Since six pieces of data on the sense of burden can be obtained within the time to reach the maximum value, a functional model of the sense of burden that changes over time into a waveform can be estimated, and the maximum value of the sense of burden and the time at which it appears can be estimated, making the lower limb sense of burden evaluation process utilizing reflex action function practical.

FIG. 8 shows the load and sense of strain on the knee joints of the leading and trailing legs over time during an ascent cycle. The load changes in a wavy pattern over time, and the same wave pattern continues even when the ascent cycle is repeated (FIG. 8A). The sense of strain changes in a wavy pattern that increases over time because the muscles and ligaments become fatigued and their resistance decreases with each ascent cycle (FIG. 8B).
If the pulling force of the electric winch or the braking force of the brake unit is increased during the lifting cycle, the burden can be reduced (FIG. 8C).
In addition, if the user pauses during the ascending and descending cycle, the movement time increases, the resistance is restored, and the sense of strain is reduced (Fig. 8D).
By using a lower limb strain feedback control process and setting appropriate pulling force, braking force, and movement time intervals, the strain can be kept within the appropriate range of lower limb strain, allowing the user to ascend and descend without injury, expanding the range of activity, and leading to a long and healthy life.
It prevents falls caused by too much load and not enough strength to support it, or too little load and feeling like it's floating, making it unstable and losing balance.
In addition, the user can intentionally change the grip strength of the hand gripping the built-in strain gauge 16 to increase or decrease the pulling force or braking force, and can also change the load on the lower limbs by changing the movement time interval, so that the user can select any load within the applicable range of load on the lower limbs when ascending or descending.

1 is a block diagram of a portable stair-climbing/descent limb strain control device according to one embodiment of the present invention; FIG. 2 is a diagram showing the configuration of a brake unit according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a gripper according to an embodiment of the present invention. The external force vector and load of the knee joint when ascending in one embodiment of the present invention. [A] is using the upper and lower limbs, [B] is using the upper and lower limbs and a small rope pulling force, and [C] is using the upper and lower limbs and a large rope pulling force. External force vectors and loads on the ankle joints when descending stairs in one embodiment of the present invention. [A] shows the use of upper and lower limbs, [B] shows the use of upper and lower limbs and a small rope tension, and [C] shows the use of upper and lower limbs and a large rope tension. For comparison, the figures in Figures 4 and 5 were standardized with the same acceleration inertia moment, and were created with reference to Non-Patent Documents 2 and 3. The body was a rigid link model. FIG. 2 is a block diagram of a lower limb strain feedback control process according to an embodiment of the present invention. This is an explanatory diagram of the feasibility of the reflex action function-based lower limb burden assessment process, created using Figures 4 and 5 in Non-Patent Document 5. [A] is the load per elapsed time on the knee joint, which is subject to a large load when ascending stairs, and [B] is the load per elapsed time on the ankle joint, which is subject to a large load when descending stairs. This is a graph of the load and feeling of strain over time when ascending stairs, created based on Fig. 7A. [A] is the load on the knee joint of the leading or rear leg when ascending stairs, [B] is the feeling of strain on the knee joint of the leading or rear leg when ascending stairs, [C] is the feeling of strain on the knee joint of the leading or rear leg when ascending stairs when the pulling force is increased, and [D] is the feeling of strain on the knee joint of the leading or rear leg when ascending stairs when there is a temporary pause.

FIG. 1 is a block diagram of a portable stair climbing/descending limb strain control device. The brake unit 5 is disposed behind the body, and the grip unit 4 is disposed on the stair railing in front of the body.
When descending the stairs, the brake unit 5 gripping the stair handrail 10 is pulled and moved, so if the stair handrail 10 is interrupted along the way or has a shape that makes it impossible to grip it using handrail fixing brackets attached to the wall, the user will have to move away from the stair handrail 10 at that point, exposing them to the risk of falling. Also, if the gripping part of the stair handrail 10 is lower than the waist belt 1 when going up or down, there is no load-relief effect, so it is desirable to install a new stair handrail 10 with gripping part 4 higher than the waist belt 1, without any gaps, and with a shape suitable for gripping.

The optimal method for moving the handrail elevator 18 is to stop the electromagnet B24 in the brake section 5 of the handrail elevator and the electromagnet A13 in the grip section when ascending or descending, and to open the tension spring by gripping the contact sensing electric signal terminal 17 in the grip section 4 with the hand, and then to carry the handrail elevator 18 by hand to the next destination without removing it from the staircase handrail 10 at the user's desired travel time interval, and then to operate the electromagnet A13 again after installation to secure it to the staircase handrail.
A mechanical transportation method may be used if it does not require facility modification work, has a shape and weight that does not occupy stairs, and allows users to travel at any desired time interval.

Figure 2 is a diagram showing the structure of the brake unit. The most accurate and optimal method is to use a pressure converter 8 to adjust the frictional force, but it is also possible to use a less accurate method in which the rope 3 is directly connected to both bottom parts of the brake base 6 and the tension in the rope 3 generated by the descent acceleration is converted into pressure/friction force between the friction part 7 of the brake unit and the staircase handrail 10.

In the case of a cylindrical staircase handrail, the optimum shape for the brake base 6 is a cylinder that can be opened and closed vertically so that pressure is applied evenly to the staircase handrail 10, but if the shape of the staircase handrail is different, a shape appropriate to that shape should be used.

FIG. 3 is a structural diagram of the grip part, and it is optimal that the shape of the friction part 15 of the grip part matches the shape of the handrail so as to increase the friction area.

FIG. 4C shows the external force vector and load on the knee joint when ascending a step. The strain gauge 16 built into the grip of the grip part is grasped by the hand, the electromagnet A 13 of the grip part is charged, and charging of the electromagnet B 24 of the brake part is stopped.

FIG. 5C shows the external force vector and load on the ankle joint when descending stairs. The strain gauge 16 built into the grip of the grip part is grasped by the hand, and the electromagnet A 13 of the grip part and the electromagnet B 24 of the brake part are charged.

In order to keep the sense of strain in the appropriate range of the sense of strain in the lower limbs, it is most accurate and optimal to use a feedback control process for the sense of strain in the lower limbs.
If the lifting speed is high, and the product of the body's reflex action time (the communication speed of the circuit, which is said to be half of the high speed, and the reaction time related to the torque of the electromagnets in the electric winch and brake unit, if these are significant for calculation, is the sum of these) and the number of data points that can estimate the functional model of the sense of burden exceeds the time to reach the maximum value, the lower limbs' sense of burden feedback control method alone cannot control it,
Although the accuracy is reduced, a feedforward control method using a general or individual burden function model for each ascending/descending condition created in advance may be used.

The industrial applicability of the present invention is to use it for ascending and descending stairs in apartment buildings, ordinary homes, or public places that are not equipped with elevators or escalators, to provide rehabilitation aids, and to control man-machine systems that utilize the body's reflex actions.

1 Waist belt 2 Electric winch 3 Rope 4 Grip part 5 Brake part 6 Brake base 7 Friction part of brake part 8 Pressure converter 9 Electric operation control device 10 Staircase handrail 11 Signal communication line 12 Power line 13 Electromagnet A
14 Tension spring 15 Friction part of grip 16 Handle built-in strain gauge 17 Contact sensing electric signal terminal 18 Handrail lift 19 Gravity 20 Acceleration inertia force 21 Rope pulling force 22 Reaction force of handrail pulling force by hand 23 Floor reaction force 24 Electromagnet B
25 Angle meter 26 Accelerometer 27 Reaction force moment of handrail pulling force by hand 28 Rope pulling force moment 29 Floor reaction force moment 30 Center of gravity moment 31 Acceleration inertia force moment 32 Upper body center of gravity 33 Center of gravity 34 Hip joint 35 Knee joint 36 Ankle joint

Claims (3)

A handrail lift comprising a gripping unit that is held by hand and moved along the handrail while repeatedly gripping and releasing the handrail, and a brake unit that grips the handrail and generates friction;
A rope connected to the gripping portion, an electric winch connected to the other end of the rope, and a waist belt connected to the electric winch;
A portable stair climbing/descent limb strain control device including a rope connected to the brake unit, a waist belt connected to the other end of the rope, an accelerometer, a handle-integrated strain gauge attached to the grip unit and held by the hand of a person ascending or descending, a goniometer installed on the rope, and an electric operation control device,
A portable stair-ascending and -descending limb strain control device characterized in that the handrail lift is of a shape and weight that allows the person ascending or descending the staircase to carry, move and set it up along the handrail of the staircase, and the electric winch, electric operation control device, angle meter and accelerometer are of a shape and weight that allows them to be attached to a waist belt. When ascending the stairs, the staircase handrail is gripped by the electromagnet and friction part constituting the gripping part, and the rope connected by the electric winch is pulled, so that the person wearing the waist belt is pulled upwards.
When descending the stairs, the electromagnet and friction part constituting the brake unit generate frictional force with the stair railing, and the connected rope is pulled, pulling the person wearing the waist belt in the opposite direction to descending the stairs, upwards.
2. The portable limb load control device for ascending and descending stairs according to claim 1, characterized in that the load on the lower limbs is shared and relieved by the lower back. The grip strength of the person ascending or descending the stairs, which is kinetically linked to the sense of strain on the lower limbs, is measured using the strain gauge built into the handle to estimate the sense of strain on the lower limbs, the angle meter measures the pulling angle of the rope, and the accelerometer estimates the acceleration inertia force of the ascending or descending motion,
The portable stair-ascending and -descending limb strain control device according to claim 1, characterized in that the electric operation control device controls the applied voltage of the electric winch and the brake unit electromagnet, thereby enabling the user to ascend and descend stairs within an appropriate range of lower limb strain.