JP2024065996A - Operation function improving device and operation function improving method - Google Patents

Abstract

[Problem] The present invention provides a device and method for improving movement function that can improve the motor function of the brain, nerves, and muscles by repeating voluntary movements that do not require excessive effort by the subject. [Solution] Based on a bioautoregulation loop that is interactively promoted between the subject's body and a movement mechanism, the difference is corrected by a movement command from the brain and nerve system, and the synthesized control state is feedback-adjusted so that the difference between the subject's movement intention and the movement phenomenon is minimized. [Selected Figure] Figure 5

Description

The present invention relates to a device and method for improving movement function, and is particularly suitable for use in the treatment and rehabilitation of subjects with functional disorders of the nervous system and physical system.

In recent years, various devices have been developed to assist or act on behalf of subjects with motor impairments. For example, wearable motion assistance devices that can control and assist movements based on bioelectric potentials associated with voluntary muscle activity according to the subject's intentions have become widespread (see, for example, Patent Document 1).

Such wearable motion-assist devices can not only assist the subject in moving according to his or her will, but can also be used, for example, in treatments and rehabilitation aimed at restoring motor function. In particular, there have been many reported cases in which subjects with disorders of the brain, nerves, or muscular system have improved their function by using wearable motion-assist devices like those described above.

When the wearable motion-assist device functions based on signals from the subject's nervous system and moves the body, which has impaired motor function, the subject ends up moving their musculoskeletal system of their own volition, and information from the sensory system flows to the nervous system through both inside and outside the body, creating a two-way biofeedback loop between the nervous system and the musculoskeletal system.

By repeating this process, it is believed that the synaptic connections of the brain, nerves, and muscles are strengthened, relearning and functional regeneration are promoted, and the physical functions of subjects with diseases of the brain, nervous system, or muscles are improved (see, for example, Non-Patent Document 1).

Patent No. 4178185

Yoshiyuki Sankai and Hiroshi Tanaka, "New Robot Medical Device for Improving Lower Limb Motor Function," 14th New Machinery Promotion Award Winners Achievement Summary, 2016, pp.5-8

Humans are able to perform voluntary movements based on their will by adaptively adjusting movement patterns that coordinate the activation of multiple muscles, such as flexors and extensors. However, the mechanism by which these various muscle groups coordinate to perform the desired movements has remained largely unexplored.

In medicine, experimental research is being conducted to elucidate information processing focusing on the brain, such as using model animals to explore how the nervous system generates specific movement patterns, and using connectome (a comprehensive map of connections within the nervous system) analysis research (connectomics) to explore the circuit structures through which nerve cells control movement.

However, experimental research focused on the brain to understand information processing cannot address the motor functions of the body, making it difficult to understand coordinated voluntary movements.

Furthermore, even in experimental research that includes not only the brain but also the body systems, if the wearable motion-assistance device described above is not used, it would be extremely difficult to prove that when a subject performs a specific voluntary movement, voluntary movement command signals to move body parts and sensory signals generated by successfully moving the body parts travel between the central system (brain and spinal cord) and peripheral systems (motor nerves, muscular system, and sensory nerves) to improve and reconstruct the body functions required for voluntary movement.

The present invention has been made in consideration of the above points, and proposes a movement function improvement device and a movement function improvement method that can improve the motor functions of the brain, nerves, and muscles by having the subject repeat voluntary movements.

In order to solve such problems, the present invention includes a motion mechanism unit that is used to be integrated with the subject and has a drive unit that is driven actively or passively in conjunction with the subject's physical movements, a signal detection unit that detects changes in ionic current transmitted from the subject's nervous system to the muscular system as bioelectric potential signals that appear on the skin surface, a joint circumference detection unit that detects physical quantities around the joints associated with the subject's physical movements based on the output signal from the drive unit, an optional control unit that controls the drive unit so that a movement phenomenon reflects the subject's intention to move based on the bioelectric potential signals and the physical quantities around the joints, and a data storage unit that stores reference parameters for each of the phases, which are a series of smallest units of movement that make up the subject's movement pattern classified as a task, and detects the phases of the subject's task by comparing the physical quantities around the joints with the reference parameters stored in the data storage unit. The system is equipped with an autonomous control unit that estimates the speed of the robot and controls the drive unit to generate power according to the phase, and a synthesis control unit that stores the control ratios of the voluntary control unit and the autonomous control unit set for each phase of each task in a data storage unit and synthesizes the control states by the voluntary control unit and the autonomous control unit to achieve a control ratio according to the phase. The synthesis control unit compensates for the physical impedance of the entire system consisting of the entire device and the subject, based on the physical quantities around the joints, in accordance with the physical characteristics of the entire system including the subject's body characteristics and gravity, and feedback-adjusts the synthesized control state while correcting the difference by the motion command from the brain and nervous system based on a bioautoregulation loop that is interactively promoted between the subject's body and the motion mechanism unit so that the difference between the subject's motion intention and the motion phenomenon is minimized.

As a result, when the subject repeatedly performs voluntary movements using the movement mechanism of the movement function improvement device, the motor function of the subject's brain, nerves, and muscles can be improved by correcting the difference between the movement commands from the brain and nervous system and the actual movement phenomenon.

The present invention also includes a center of gravity detection unit that detects the center of gravity of the subject based on changes in load on the soles of the feet of the subject, and a walking state recognition unit that recognizes the walking state of the subject based on the control state by the synthesis control unit and the center of gravity position by the center of gravity detection unit, and the optional control unit controls the drive unit to produce a movement phenomenon that reflects the subject's intention to move based on the bioelectric potential signal, physical quantities around the joints, and the walking state recognized by the walking state recognition unit.

As a result, the movement function improvement device enables the subject to walk safely even when the subject has difficulty moving the lower limbs on his/her own, and at the same time, when the voluntary control unit controls the drive unit, the accuracy of the movement phenomenon that reflects the subject's movement intention can be improved.

Furthermore, in the present invention, when forming a bioautoregulation loop, the smallest motor control unit for realizing voluntary movements caused by the will of the subject is set as a minimum voluntary motor control unit consisting of the brain nervous system, synaptic connections, and muscular system, and a bioautoregulation loop is established for each minimum voluntary motor control unit that forms bodily movements that are linked to realize a motor phenomenon using a motion mechanism.

As a result, in the movement function improvement device, the minimum voluntary movement control unit is explicitly incorporated into the process of function improvement and treatment based on the basic theory of the biological self-control loop by the movement mechanism, which is influenced by the diseased area and disease cause. This has an effect on the other minimum voluntary movement control units, and they work in sync with the movement of the movement mechanism, strengthening and adjusting the functions of each minimum voluntary movement control unit in sync with the movement of the movement mechanism to achieve the target movement, improving the function of the brain, nerves, and muscles.

Furthermore, in the present invention, the joint detection unit detects the absolute angle between the rotor side frame and the stator side frame of the drive unit in the motion assist device, the rotation angle, the angular velocity, the angular acceleration, and the drive torque as physical quantities around the joint.

Furthermore, in the present invention, when an operating mechanism unit having a drive unit that is driven actively or passively in conjunction with the subject's physical movements is used as one with the subject, the operating mechanism unit includes an optional control step of controlling the drive unit so as to produce a movement phenomenon that reflects the subject's intention to move, based on a bioelectric potential signal that appears on the skin surface representing a change in ionic current transmitted from the subject's nervous system to the muscular system of the subject, and on physical quantities around the joints associated with the subject's physical movements detected based on an output signal from the drive unit, and a data storage unit that stores reference parameters for each of the phases, which are a series of minimum movement units that constitute the subject's movement pattern classified as a task, and by comparing the physical quantities around the joints with the reference parameters stored in the data storage unit, estimates the phase of the subject's task, and controls the drive unit to generate power corresponding to that phase. The system includes an autonomous control step that controls the subject's motion and an autonomous control step that stores the control ratio of the autonomous control step and the voluntary control step set for each phase of each task in a data storage unit and synthesizes the control state by the autonomous control step and the voluntary control step so as to obtain a control ratio according to the phase. In the synthesis control step, the physical impedance of the entire system consisting of the entire device and the subject is compensated for in accordance with the physical characteristics of the entire system including the subject's body characteristics and gravity based on the physical quantities around the joints, and the synthesis control step feedback-adjusts the synthesized control state while correcting the difference by the motion command from the brain and nervous system based on the bioautoregulation loop interactively promoted between the subject's body and the motion mechanism unit so as to minimize the difference between the subject's motion intention and the motion phenomenon.

As a result, in the method for improving movement function, when the subject repeatedly performs voluntary movements using the movement mechanism, the motor function of the subject's brain-nerve-muscle system can be improved by correcting the difference between the movement command from the brain-nerve-muscle system and the actual movement phenomenon.

According to the present invention, it is possible to realize a movement function improvement device and a movement function improvement method that can improve the motor function of the subject's brain-nerve-muscle system by correcting the difference between the movement command from the brain-nerve-muscle system and the actual movement phenomenon when the subject repeatedly performs voluntary movements using a movement mechanism.

FIG. 1 is a conceptual diagram for explaining the basic theory of the bioautoregulation loop according to the present invention. FIG. 2 is a conceptual diagram illustrating a minimum voluntary movement control unit. FIG. 1 is a conceptual diagram showing a transition state when the basic theory of the bioautoregulation loop described above is applied to a subject. 1 is a schematic diagram showing an external configuration of a lower limb type motion function improving device according to an embodiment of the present invention; FIG. 5 is a block diagram showing the configuration of a control system of the motion function improving device of FIG. 4. FIG. 2 is a conceptual diagram showing an example of each task and each phase stored in a data storage unit. 13 is a schematic diagram showing the external configuration of a motion function improving device including a waist-type motion mechanism unit in another embodiment. FIG. 8 is a schematic diagram showing a main configuration of the operation function improving device of FIG. 7; 8 is a schematic diagram showing the operation state and the movable range of the motion improving device of FIG. 7; 13 is a schematic diagram showing the external configuration of a motion function improving device including a single-joint type motion mechanism unit in another embodiment. FIG. 11 is a schematic diagram showing a state in which the motion function improving device of FIG. 10 is applied to the knee joint of the right leg of a subject. 11 is a schematic diagram showing a state in which the motion function improving device of FIG. 10 is applied to the elbow joint of the left arm of a subject. FIG. 1 is a diagram showing the state in which the movement function improving device is worn by a subject. FIG. 1 is a diagram showing the state in which the movement function improving device is worn by a subject.

One embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Basic theory of the biological self-regulation loop in the present invention As a method for improving the motor function of a subject's brain-nerve-muscle system, experimental research has been conducted medically to elucidate information processing focusing on the brain. However, with brain research alone, it is difficult to target the body's motor functions because the brain is separated from the motor system.

The human body's motor system is made up of the central nervous system (brain and spinal cord), the peripheral nervous system, and the musculoskeletal system. When dealing with the flow of information from the efferent nerves that leave the central nervous system and head toward the periphery, these systems form a connected information transmission system, but this alone does not allow for proper motor control.

In other words, information from efferent nerves is transmitted to the muscle fibers involved in muscle contraction, but even if information after contraction is transmitted from the brain to the spinal cord and then to the motor nerves and muscle fibers, the information does not return to the brain. For this reason, it is nearly impossible to clarify the mechanism for improving motor function or to develop techniques to improve motor control simply by analyzing the "motor unit" consisting of motor nerves and muscle fibers.

For this reason, some research has attempted to improve function by using robot technology to move the joints and muscles of the legs, hands, etc. through external motion input to those systems; however, it has also been reported that simply applying an external force to move the joints and muscles of the legs, hands, etc. does not result in improved function.

As shown in Figure 1, in this invention, a movement mechanism having a drive unit that drives actively or passively in conjunction with the subject's physical movements is used to demonstrate that when the subject performs a specific movement, command signals (efferent nerve signals) that cause the subject to move in accordance with their motor intention, and sensory signals (afferent nerve signals) generated by successfully moving the subject, travel between the central system (brain and spinal cord) and peripheral systems (motor nerves, muscular system, and sensory nerves), improving and reconstructing the physical functions required for voluntary movement.

The movement function improvement method according to the present invention includes a voluntary control step for making the subject move in accordance with his/her movement intention, an autonomous control step for generating a preset ideal power, and an impedance control step (including gravity compensation control) for reducing the feeling of difficulty in moving due to the load and viscous friction of the movement mechanism itself, so that the subject can feel as if the movement mechanism is a part of his/her body, and it is possible to realize a functional fusion and integration between the subject and the movement mechanism.

Furthermore, in this method for improving movement function, the synthesis control step that synthesizes the control states from the voluntary control step and the autonomous control step so as to obtain a control ratio according to the phase of the task not only executes the impedance control step described above, but also feedback-adjusts the synthesized control state while simultaneously correcting the difference by the movement command from the brain and nervous system based on a bioautoregulation loop that is interactively promoted between the subject's body and the movement mechanism so as to minimize the difference between the subject's movement intention and the motor phenomenon.

This biological self-regulation loop is formed by activating proprioceptors called muscle spindles and tendon spindles in muscles and tendons in synchronization with nervous system command information transmitted from the brain through the spinal cord and motor nerves to muscle fibers and muscle contraction, and this activation information becomes information on muscle contraction and is fed back to the central nervous system (spinal cord and brain) via sensory nerves, and the feedback information is used to strengthen and adjust the synaptic connections between nerves and between nerves and muscles, in a repeated circular flow.

In this way, with the movement function improvement method, when the subject repeatedly performs voluntary movements using the movement mechanism, the motor function of the subject's brain-nerve-muscle system can be improved by correcting the difference between the movement command from the brain-nerve-muscle system and the actual movement phenomenon.

One of the features of the present invention is that when forming a biological autoregulation loop, a minimum voluntary movement control unit consisting of the cranial nervous system (brain and spinal cord), synaptic connections (nerve-nerve synaptic connections and nerve-muscle synaptic connections), and muscular system (muscle fibers (extrafusal muscle fibers connected to alpha motor neurons and intrafusal muscle fibers connected to gamma motor neurons), tendon fibers, muscle spindles, tendon spindles, etc.) can be configured as the minimum movement control unit to realize voluntary movements caused by human will to establish a biological autoregulation loop.

In other words, the minimum voluntary movement control unit is a control unit for realizing the minimum voluntary movement, which is formed through the pathways of the cranial nervous system (brain, spinal cord, motor nerves), muscle fibers, movement (reaction), muscle spindles, tendon spindles, and the cranial nervous system (sensory nerves, spinal nerves, brain) as shown in Figure 2.

The minimum voluntary movement control unit that creates a specific joint movement is configured in multiple units in conjunction with other minimum voluntary movement control units that are related to the minimum voluntary movement unit in conjunction with other joint movements, thereby realizing the desired overall movement.

During this process, the synaptic connections between the nerves in the minimal voluntary motor control units, and between the nerves and the muscles, are adjusted and strengthened within the group of minimal voluntary motor control units related to the target overall movement and within the overall adjustment system, such as the unconscious adjustment of postural balance.

Furthermore, in joint movements driven by muscle groups (so-called flexion and extension muscle groups) composed of the smallest voluntary movement control units (units), and in more complex coordinated movements composed of each joint system, by using a movement mechanism (such as the lower limb type, single joint type, waist type, hand type, and finger type described below), it is possible to accommodate everything from the smallest units to highly complex body systems, thereby achieving functional improvements in the brain, nerves, and muscles.

In fact, if the minimum voluntary movement control unit is considered to be a unit that promotes synaptic plasticity, neuroplasticity, and muscular plasticity, which are basic neural functions for improving the function of the brain, nerves, and muscles, the process for activating the subject's self-healing ability in response to the disease or symptoms (relaxation, stiffness, tremors, rigidity, ataxia, simultaneous contraction, etc.) will differ for each minimum voluntary movement control unit.

Therefore, the unit components of the minimum voluntary movement control unit for improving the motor functions of the brain-nerve-muscle system differ for each disease or symptom, and the relevant parts and ranges of other minimum voluntary movement control units related to the minimum voluntary movement control unit also differ, so it is possible to construct a treatment control strategy by using it as the minimum unit when making various adjustments to the movement mechanism according to the subject's condition (such as tuning parameters to realize movements according to the subject's movement intentions and establish a bioautoregulation loop).

In the method for improving movement function according to the present invention, signals derived from the nervous system linked to voluntary will obtained from a pathway affected by the disease site or cause of disease are detected, and then functional improvements are implemented for each of the minimum voluntary movement control units that make up the overall voluntary movement that is the target, focusing on the minimum voluntary movement control units involved in that pathway.

The starting point for a human to perform voluntary movements is the expression of the will to perform a voluntary movement in the cerebrum, and the nervous system signals of that will to move are transmitted from the brain to the spinal cord, motor nerves, and muscle fibers, ultimately achieving the desired movement. However, this process, from the expression of will to the generation of a movement, is too rough, making it difficult to explicitly grasp the influence of the diseased area and disease cause on voluntary movements from the brain/nervous system through synaptic connections to the muscular system, including the sensory nerves of muscle fibers and muscle spindles and the gamma loop of gamma motor neurons. It is also difficult to explicitly perform treatment that takes into account the influence of the diseased area and disease cause. For this reason, in actual clinical settings, training is limited to the repetition of simple movements.

Therefore, by explicitly incorporating a minimum voluntary movement control unit that reflects the influence of the diseased area and disease cause into the process of functional improvement treatment based on the basic theory of the biological self-regulation loop by the movement mechanism, the effect is also felt on the other minimum voluntary movement control units, and they work in sync with the movement of the movement mechanism, and in order to achieve the target movement, the functions of the individual minimum voluntary movement control units are strengthened and adjusted in sync with the movement of the movement mechanism, making it possible to improve the functions of the brain, nerves, and muscles as a new method that differs from conventional methods.

Figures 3 (A) to (E) show the transitional states when the basic theory of the bioautoregulation loop described above is applied to a subject. Starting from a state before treatment where the movement mechanism is not attached (Figure 3 (A)), in the early stages of treatment, sensory nervous system information from the musculoskeletal system caused by joint movement using the movement mechanism is fed back to the central nervous system (brain and spinal cord) (Figure 3 (B)).

Next, after the initial treatment, when the movement mechanism is not attached (Fig. 3(C)), some feedback sensation of sensory nervous system information remains, but by continuing treatment using the movement mechanism (Fig. 3(D)), the difference between the subject's movement intention and the motor phenomenon is corrected by movement commands from the central nervous system based on the bioautoregulation loop that is interactively promoted between the subject's body and the movement mechanism.

Even after continuous treatment, when the movement mechanism is not attached, the motor function of the subject's brain-nerve-muscle system can be improved while activating the subject's self-healing powers by correcting the difference between the movement commands from the central nervous system and the actual movement phenomenon (Figure 3 (E)).

(2) Movement Function Improvement Device in the Present Embodiment (2-1) Configuration of the Movement Mechanism (Lower Limb Type: Hardware)
The configuration of a motion function improving device including a motion mechanism for the lower body (lower limb type) in this embodiment will be described.

As shown in FIG. 4, the movement function improving device 1 is used to be integrated with the subject, and is configured by incorporating a control system 3 (FIG. 5) having the functional configuration of the basic theory of the above-mentioned voluntary control step, autonomous control step, impedance control step, and bio-autonomic control loop in a movement mechanism unit 2 having a drive mechanism that drives actively or passively in conjunction with the subject's physical movements.

The movement function improvement device 1 is a device that applies to the subject a driving force that is autonomously controlled in accordance with each walking phase that constitutes the walking movement of the subject, and a driving force that is voluntarily controlled based on a bioelectric potential signal. It detects the bioelectric potential signal and the movement angles of the subject's hip joint and knee joint, and operates to apply a driving force from a drive mechanism based on the detection signal.

The operating mechanism unit 2 is composed of a waist frame 10 attached to the waist of the subject, a lower limb frame 11 attached to the lower limbs of the subject, a number of drive units (drive mechanisms) 12L, 12R, 13L, 13R provided on the lower limb frame 11 corresponding to the joints of the subject, and cuffs 14L, 14R, 15L, 15R as auxiliary force application members attached to the lower limb frame 11 so that the forces of the drive units 12L, 12R, 13L, 13R act on the subject from the front or rear.

In addition to the above-mentioned movement mechanism unit 2, the movement function improvement device 1 has a control device 30 (see FIG. 5 below) that controls the drive units (drive mechanisms) 12L, 12R, 13L, and 13R based on signals resulting from the subject's lower limb movements, a rear unit 16 equipped with the control device 30, and an operation unit (not shown) used by the caregiver.

The control device 30 (Fig. 5) can drive the lower limb frames 11 relatively around the output axes of the actuators of the drive units 12L, 12R, 13L, and 13R that correspond to the joints of the subject. Each drive unit 12L, 12R, 13L, and 13R is equipped with a group of sensors for detecting the drive torque and rotation angle of the actuator. The rear unit 16 is equipped with a battery unit (not shown) for supplying power to drive the entire device.

The waist frame 10 is a generally C-shaped member in plan view that opens forward and can receive the subject's waist and enclose it from its rear to both left and right sides. It has a rear waist frame part 17 located behind the subject, and a left waist frame part 18L and a right waist frame part 18R that extend forward while curving from both ends of the rear waist frame part 17.

The left and right hip frame sections 18L and 18R are connected to the rear hip frame section 17 via an opening adjustment mechanism (not shown). The bases of the left and right hip frame sections 18L and 18R are inserted and held within the rear hip frame section 17 so that they can slide left and right.

The lower limb frame 11 has a right lower limb frame 19R that is attached to the right lower limb of the subject, and a left lower limb frame 19L that is attached to the left lower limb of the subject. The left lower limb frame 19L and the right lower limb frame 19R are formed symmetrically.

The left lower leg frame 19L has a left thigh frame 20L located on the left side of the subject's left thigh, a left lower leg frame 21L located on the left side of the subject's left lower leg, and a left lower leg frame 22L on which the sole of the subject's left leg (the sole of the left shoe if shoes are worn) is placed. The left lower leg frame 19L is connected to the tip of the left waist frame section 18L via a waist connection mechanism 23L.

The right lower leg frame 19R has a right thigh frame 20R located on the right side of the subject's right thigh, a right lower leg frame 21R located on the right side of the subject's right lower leg, and a right lower leg frame 22R on which the sole of the subject's right leg (the sole of the right shoe if shoes are worn) is placed. The right lower leg frame 21R is connected to the tip of the right waist frame section 18R via a waist connection mechanism 23R.

The waist frame 10 (rear waist frame 17, right waist frame 18R, and left waist frame 18L) and the lower leg frame 11 (right lower leg frame 19R and left lower leg frame 19L) have a frame body formed into a long, thin plate shape, for example, from a metal such as stainless steel or carbon fiber, and are formed to be lightweight and highly rigid. In this embodiment, carbon fiber reinforced plastic (CFRP) and extra super duralumin, an aluminum alloy, are used as strength members.

Cuffs 14L, 14R, 15L, and 15R are provided on each of the left thigh frame 20L, right thigh frame 20R, left lower leg frame 21L, and right lower leg frame 21R.

The cuffs (hereafter referred to as "thigh cuffs") 14L, 14R provided on the left thigh frame 20L and right thigh frame 20R are supported by thigh cuff support mechanisms 24L, 24R attached to the lower ends of the thigh frame bodies. The thigh cuffs 14L, 14R have an arc-shaped attachment surface that can be fitted and placed against the subject's thigh. A fitting member is attached to the attachment surface of the thigh cuffs 14L, 14R so that they can fit closely to the subject's thigh without any gaps.

The cuffs (hereinafter referred to as "calf cuffs") 15L, 15R provided on the left crus frame 21L and right crus frame 21R are supported by crus cuff support mechanisms 25L, 25R attached to the upper ends of the upper elements. The crus cuffs 15L, 15R have an arc-shaped attachment surface that can be fitted and placed against the subject's crus. A fitting member is attached to the attachment surface of the crus cuffs 15L, 15R so that they can fit snugly against the subject's crus.

When actually putting this movement function improving device on a subject, special shoes 26L, 26R are put on the left and right feet, respectively, lower leg cuffs 15L, 15R are put on the left and right lower legs, respectively, and thigh cuffs 14L, 14R are put on the left and right thighs, respectively. Then, belts or the like are fastened to the shoes and cuffs so that the feet, lower legs, and thighs are integrated with the corresponding frames.

These special shoes 26L, 26R are made up of a pair of left and right shoes that hold the subject's feet in a tight fit from the toes to the ankles, and can measure load using a floor reaction force sensor (FRF sensor 60, described below) attached to the sole of the foot.

In this way, the movement function improvement device 1 can control and assist walking movements based on bioelectric potential signals that accompany voluntary nervous system command signals according to the intentions of the subject wearing the movement mechanism unit 2.

(3) Control System in the Motion Function Improvement Device Fig. 5 is a block diagram showing the configuration of the control system 3 of the motion function improvement device 1. As shown in Fig. 5, the control system 3 of the motion function improvement device 1 has a control device 30 that is responsible for overall control of the entire system, a data storage unit 31 in which various data is stored in a database so as to be readable and writable in response to commands from the control device 30, and drive units 12L, 12R, 13L, and 13R that actively or passively drive in conjunction with the lower limb movement of the subject.

The control system 3 is also provided with a joint detection unit 40 having a potentiometer 32, an absolute angle sensor 33, and a torque sensor 34, and detects the physical quantities around the joints associated with the subject's body movements based on the output signals from the drive units 12L, 12R, 13L, and 13R.

The joint detection unit 40 detects the physical quantities around the joints, such as the absolute angle, rotation angle, angular velocity, angular acceleration, and drive torque between the rotor side frame and the stator side frame of the drive units 12L, 12R, 13L, and 13R in the operating mechanism unit 2.

The potentiometer 32 is coaxial with the output shaft of the actuator in the drive units 12L, 12R, 13L, and 13R, and detects the rotation angle of the output shaft to detect the joint angle corresponding to the movement of the subject's lower limbs.

The absolute angle sensor 33 is also mounted on the lower limb frame 11 and measures the absolute angle of the subject's thigh relative to the vertical direction. This absolute angle sensor 33 is composed of an acceleration sensor and a gyro sensor, and is used in sensor fusion, which is a method of extracting new information using data from multiple sensors.

To calculate the absolute thigh angle, a first-order filter is used to remove the effects of translational motion and temperature drift in each sensor. This first-order filter is calculated by weighting and adding up the values obtained from each sensor.

If the absolute angle of the thigh with respect to the vertical direction is θabs(k), the angular velocity obtained by the gyro sensor is ω, the sampling period is dt, and the acceleration obtained by the acceleration sensor is α, then θabs(t) can be expressed as in the following equation (1).

Furthermore, the torque sensor 34 detects the current value supplied to the drive units 12L, 12R, 13L, and 13R, for example, and detects the drive torque by multiplying this current value by a torque constant specific to the actuator.

A biosignal detection unit 41 having a bioelectric potential sensor (electrode group) is placed on the subject's body surface (mainly the body surface of the thigh) based on the joints associated with the subject's lower limb movements, and detects changes in the ionic current transmitted from the subject's cranial nervous system to the muscular system as a bioelectric potential signal that appears on the skin surface.

The biosignal detection unit 41 is a detection unit that measures nerve action potentials emitted from the brain toward the legs to move the subject's legs and muscle action potentials when skeletal muscles generate muscle force, and has electrodes that detect weak potentials generated at the periphery of the body system. In this embodiment, the biopotential sensor is attached so that it can be detachably attached to the subject's skin surface, for example, by an adhesive sticker that covers the periphery of the electrode.

The data storage unit 31 stores data required for various calculation processes in the control device 30. Bioelectric potential signals detected by the biosignal detection unit 41 are stored in the data storage unit 31. The joint angles (θknee, θhip) detected by the absolute angle sensor 33 of the joint circumference detection unit 40 and the load data detected by the FRF sensor 60 described later are input to the data storage unit 31.

The control device 30 is, for example, configured with a CPU (Central Processing Unit) chip having memory, and includes a voluntary control unit 50, an autonomous control unit 51, and a synthesis control unit 52.

The optional control unit 50 controls the drive units 12L, 12R, 13L, and 13R based on the bioelectric potential signal and the physical quantities around the joints to produce a movement phenomenon that reflects the subject's intention to move. Specifically, the optional control unit 50 supplies a command signal to the current control unit 55 in response to the detection signal from the biosignal detection unit 41.

The optional control unit 50 generates a command signal by applying a predetermined command function f(t) or gain P to the biosignal detection unit 41. This gain P is a preset value or function and can be adjusted by an external input.

The data on the knee joint angle detected by the potentiometer 32, the data on the absolute angle of the thigh relative to the vertical direction detected by the absolute angle sensor 33, the drive torque detected by the torque sensor 34, and the bioelectric potential signal detected by the biosignal detection unit 41 are input to the data storage unit 31.

Floor Reaction Force (FRF) sensors 60 are attached to the soles of the pair of dedicated shoes 26L, 26R to detect the pressure distribution on the soles of the subject's left and right feet. The FRF sensors 60 can measure the load acting on the soles of the feet separately for the forefoot (toes) and rearfoot (heel).

This FRF sensor 60 is composed of, for example, a piezoelectric element that outputs a voltage according to the applied load or a sensor whose capacitance changes according to the load, and can detect changes in load due to weight shifting and the presence or absence of contact between the subject's legs and the ground.

Furthermore, with the pair of dedicated shoes 26L, 26R, the center of gravity position can be obtained from the balance of the load on the soles of the left and right feet based on the detection results of each FRF sensor 60. In this way, with the pair of dedicated shoes 26L, 26R, it is possible to estimate to which side of the subject's left or right foot the center of gravity is biased, based on the data measured by each FRF sensor 60.

In addition to the shoe structure, each of the dedicated shoes 26L, 26R has an FRF sensor 60, an FRF control unit 61 consisting of an MCU (Micro Control Unit), and a transmission unit 62. The output of the FRF sensor 60 is converted into a voltage via a converter 63, and then the high frequency band is cut off via an LPF (Low Pass Filter) 64 before being input to the FRF control unit 61.

The FRF control unit (center of gravity position detection unit and walking state recognition unit) 61 determines the load change and the presence or absence of contact with the ground due to the weight shift of the subject based on the detection results of the FRF sensor 60, and also determines the center of gravity position according to the load balance on the soles of the left and right feet. The FRF control unit 61 wirelessly transmits the determined center of gravity position as FRF data via the transmission unit 62 to the receiving unit 65 in the device body.

The control device 30 receives the FRF data wirelessly transmitted from the transmitter 62 of each dedicated shoe 26L, 26R via the receiver 65, and then stores the load and center of gravity position on the soles of the left and right feet based on the FRF data in the data storage unit 31.

The autonomous control unit 51 stores in the data storage unit 31 the reference parameters for each phase, which is a series of smallest movement units that make up the movement pattern of the subject classified as a task, and estimates the phase of the subject's task by comparing the physical quantities around the joints with the reference parameters stored in the data storage unit 31, and controls the drive unit to generate power corresponding to that phase.

The autonomous control unit 51 compares the knee joint angle data detected by the joint circumference detection unit (potentiometer 32) 40 and the load data detected by the FRF sensor 60 with the knee joint angle and load of the reference parameters stored in the data storage unit 31, and estimates the phase of the subject's movement based on the comparison result.

Then, when the autonomous control unit 51 obtains the control data for the estimated phase, it generates a command signal according to the control data for this phase and supplies the command signal to the current control unit 55 to generate this power in the drive units 12L, 12R, 13L, and 13R.

The autonomous control unit 51 also receives a gain adjusted by an external input, generates a command signal according to this gain, and outputs it to the current control unit 55. The current control unit 55 controls the current that drives the actuators of the drive units 12L, 12R, 13L, and 13R to control the magnitude of the torque and the rotation angle of the actuators, thereby applying an assist force from the actuators to the knee joint of the subject.

In this way, the autonomous control unit 51 identifies the walking phases corresponding to the walking task of the subject based on the physical quantities detected by the joint circumference detection unit (potentiometer 32, absolute angle sensor 33, and torque sensor 34) 40, and generates power corresponding to each walking phase in the drive units 12L, 12R, 13L, and 13R.

The synthesis control unit 52 synthesizes the control signals from the voluntary control unit 50 and the autonomous control unit 51, and the drive current corresponding to the synthesized control signal is amplified by the current control unit 55 and supplied to the actuators of the drive units 12L, 12R, 13L, and 13R. The torque of this actuator is transmitted to the knee joint of the subject as an assist force via the lower limb frame.

Figure 6 shows an example of each task and each phase stored in the data storage unit 31. As tasks for classifying the subject's movements, for example, task A having standing movement data for transitioning from a sitting position to a standing position, task B having walking movement data for the subject walking after standing, task C having sitting movement data for transitioning from a standing position to a sitting position, and task D having stair ascending and descending movement data for ascending and descending stairs from a standing position are stored in the data storage unit 31.

Each task is set with multiple phase data. For example, task B for walking movement has phase B with motion data (joint angles, trajectory of center of gravity position, torque fluctuation, change in bioelectric potential signal, etc.) when trying to swing the right leg forward from a standing position with the center of gravity on the left leg, phase B with motion data when landing and shifting the center of gravity from a position with the right leg forward, phase B with motion data when trying to swing the left leg forward from a standing position with the center of gravity on the right leg, and phase B with motion data when landing and shifting the center of gravity from a position with the left leg forward of the right leg.

In this way, by analyzing general human movements, it is found that there are typical movement patterns, such as the angles of each joint and the movement of the center of gravity, in each phase. Therefore, for each phase that constitutes many basic human movements (tasks), typical displacements of joint angles and the state of the movement of the center of gravity are empirically determined and stored in the data storage unit 31. In addition, multiple assist patterns are assigned to each phase, and different assistance is provided with each assist pattern, even in the same phase.

In the above configuration, the motion function improvement device 1 detects changes in the ionic current transmitted from the subject's cranial nervous system to the muscular system as a bioelectric potential signal that appears on the skin surface using the biosignal detection unit 41, and operates to apply a driving force from the drive unit (actuator) based on this detection signal.

When the subject wearing the movement mechanism unit 2 attempts to walk of their own volition, a driving torque corresponding to the bioelectric potential signal generated is applied as an assist force from the movement mechanism unit 2. In other words, the assist force is a force that generates a torque that acts on each joint in the frame mechanism of the movement mechanism unit 2 (corresponding to the subject's knee joint and hip joint, respectively) as the axis of rotation.

The subject can therefore walk while supporting his or her weight with the combined force of his or her own muscle strength and the drive torque from the drive units 12L, 12R, 13L, and 13R. In this case, the motion function improvement device 1 controls the assist force applied in response to the shift in the center of gravity accompanying the walking movement so as to reflect the subject's will. Therefore, the drive units 12L, 12R, 13L, and 13R of the motion mechanism unit 2 are controlled so as not to apply a load that goes against the subject's will, and are controlled so as not to interfere with the subject's movements.

In addition to walking, the motion function improving device 1 can also assist with motions that correspond to the subject's will, such as when the subject stands up from a seated position in a chair, or when sitting down in a chair from a standing position, or even when the subject goes up or down stairs. In particular, when muscle strength is weak, it is difficult to climb stairs or stand up from a chair, but when the subject is fitted with the motion mechanism unit 2, a driving torque is applied according to the subject's will, allowing the subject to move without worrying about weakened muscle strength.

The synthesis control unit 52 stores the control ratios of the voluntary control unit 50 and the autonomous control unit 51 set for each phase of each task in the data storage unit 31, and synthesizes the control states of the voluntary control unit 50 and the autonomous control unit 51 so that the control ratio corresponds to the phase.

In other words, when a subject tries to move his or her body, the motor intention is transmitted as a weak ionic current from the brain to the spinal cord, nerves, muscle spindles, and muscles, causing the musculoskeletal system with joints to move. When a weak bioelectric potential signal is detected from the subject's skin surface, the voluntary control unit 50 controls the actuators to move the joints according to the subject's intention.

The movement mechanism 2 is fastened in a state of close contact with the subject's legs (biological parts), etc., so that the driving forces of the drive units 12L, 12R, 13L, and 13R are transmitted to the subject as an assisting force for rotating the joints. Therefore, when the subject's body moves due to the assisting force of the movement mechanism 2, signals from the Ia afferent neurons are sent from the muscle spindles back to the brain via the nerves and spinal cord.

As a result, interactive biofeedback is formed between the subject, brain, and movement function improvement device 1, consisting of a signal transmission system of "brain → spinal cord → motor nerves → [musculoskeletal system + movement mechanism 2]" and a signal transmission system of "movement mechanism 2 → musculoskeletal system (muscle spindles) → sensory nerves → spinal cord → brain." This is bidirectional voluntary control from the brain and the movement mechanism 2, making it possible to further enhance the effects of functional recovery training of the nervous system through neurorehabilitation.

In this way, the movement function improvement device 1 is configured to sense bioelectric potential signals from the brain to the periphery after a decision is made regarding movement and utilize them for actuator control, and is intended to capture bioelectric potential signals corresponding to brain activity from peripheral muscle activity. It is then possible to provide real-time feedback to the brain and nervous system sensed at the periphery. Therefore, by carrying out rehabilitation while the subject is wearing the movement mechanism unit 2, it is possible to promote functional recovery in the two-way signal transmission system.

In addition, in cases of severe motor dysfunction where bioelectrical signals cannot be detected, voluntary control does not function, so the control ratio is switched so that autonomous control functions, controlling the drive unit using a control program for each phase based on the results of an analysis of basic human movement patterns and movement mechanisms.

In this hybrid control method, where voluntary control and autonomous control coexist, the amplitude and signal characteristics of bioelectrical signals change according to the state of the body's motor functions, even in cases of complete paralysis or the progression of an intractable neuromuscular disease, making it possible to effectively carry out rehabilitation for these conditions.

Furthermore, the synthesis control unit 52 compensates the physical impedance of the entire system consisting of the entire device and the subject based on the physical quantities around the joints, in accordance with the physical characteristics of the entire system, including the body characteristics of the subject, and gravity.

In other words, the synthesis control unit 52 constructs a target equation of motion in a computational environment using the equation of motion data (Mi) and known parameters (Pk) read from the data storage unit 31, and is configured to be able to substitute a drive torque estimate (Te), a joint torque estimate (ΔT), and a joint angle θ into the equation of motion.

The equation of motion data (Mi) is used to construct an equation of motion for the entire system consisting of the motion function improvement device 1 and the subject, while the known parameters (Pk) consist of dynamics parameters such as the weight of each part of the motion function improvement device 1, the moment of inertia around the joints, the viscosity coefficient, and the Coulomb friction coefficient.

The joint circumference detection unit 40 includes not only the potentiometer 32, absolute angle sensor 33, and torque sensor 34 described above, but also a relative force detection unit 70, a joint torque estimation unit 71, and a muscle torque estimation unit 72. The relative force detection unit 70 detects the relative force (ΔF) acting on the movement mechanism unit (frame mechanism) 2, that is, the force that is determined relatively in relation to the forces generated by the drive units 12L, 12R, 13L, and 13R and the muscle strength of the subject.

The joint torque estimation unit 71 estimates the joint moment (ΔT) around each joint of the subject from the difference between the relative force data (ΔF) detected by the relative force detection unit 70 multiplied by a preset coefficient and the drive torque (Te) detected by the torque sensor 34. The resultant force of the drive torque (Te) of the drive units 12L, 12R, 13L, and 13R and the subject's muscle torque (Tm) acts on the subject's legs as the joint moment (ΔT), so the subject can move his or her legs with less muscle force than if the movement mechanism unit (frame mechanism) 2 was not attached.

The muscle torque estimation unit 72 estimates the muscle torque (Tm) due to the subject's muscle force based on the drive torque (Te) detected by the torque sensor 34 and the joint moment (ΔT) estimated by the joint torque estimation unit 71. Note that the muscle torque (Tm) is calculated in order to enable parameter identification even when the subject is generating muscle force, which is advantageous when performing parameter identification while the subject is moving.

The synthesis control unit 52 performs calculations taking into account the drive torque (Te), joint data (θ), joint moment (ΔT), and muscle torque (Tm) obtained from the joint detection unit 40, identifies unknown dynamics parameters (Pu) such as the weight of each part of the subject, the moment of inertia around each joint, the viscosity coefficient, and the Coulomb friction coefficient, and repeats this process multiple times (e.g., 10 times) to average them.

Next, the synthesis control unit 52 reads the ratio (Tm/BES) of the estimated muscle torque (Tm) and bioelectric potential and a predetermined set gain (Gs) from the data storage unit 31, and if the set gain (Gs) is outside the allowable error range (Ea), it corrects the bioelectric potential (BES) to obtain a corrected bioelectric potential (BES') and makes the ratio (Tm/BES') of the muscle torque (Tm) and the corrected bioelectric potential (BES') approximately equal to the set gain (Gs).

As a result, it is possible to prevent a situation in which the accuracy of identifying the unknown dynamics parameters (Pu) of the subject is reduced, and also to prevent a situation in which the assisting force generated by the drive units 12L, 12R, 13L, and 13R is too small or too large.

The synthesis control unit 52 is configured to be able to read the control method data (Ci) from the data storage unit 31, the drive torque (Te), joint torque (ΔT) and joint angle θ obtained from the joint circumference detection unit 40, as well as the identification parameters (Pi) that are the results of identifying the unknown dynamics parameters (Pu), and the corrected bioelectric potential (BES').

The synthesis control unit 52 also uses the control method data (Ci) to configure a specific control unit in the computation environment, and can send a control signal Ur for controlling the drive units 12L, 12R, 13L, and 13R by reflecting the drive torque (Te), joint torque (ΔT), joint angle θ, identification parameter (Pi), and bioelectric potential (BES') in this synthesis control unit 52. The current control unit 55 drives the drive units 12L, 12R, 13L, and 13R in response to the control signal Ur from the synthesis control unit 52.

Movement function improving device 1 also controls the assist force based on impedance adjustment to eliminate the hindrance to natural control caused by the physical characteristics of the device itself, namely the viscoelasticity around the joints and the constraints caused by the inertia of the frame. That is, movement function improving device 1 calculates the parameters of the joints and compensates for the moment of inertia, viscosity, and elasticity using drive units (actuators) 12L, 12R, 13L, and 13R, thereby improving the assistance rate in walking movements and reducing the discomfort felt by the subject.

In this way, with the movement function improvement device 1, it is possible to indirectly change and adjust the characteristics of the subject by changing the characteristics of the entire system, which includes the device itself and the subject. For example, by adjusting the drive torque so as to suppress the effects of the inertia and viscous friction terms of the entire system, it is possible to maximize the subject's innate ability to perform agile movements such as reflexes. Furthermore, it is possible to suppress the effects of the subject's own inertia and viscous friction terms, making it possible to have the subject walk faster than their natural cycle or move more smoothly (with less viscous friction) than before wearing the device.

Furthermore, when the motion function improving device 1 is worn by a subject, the synthesis control unit 52 identifies the subject's specific dynamics parameters, and the control device 30 controls the actuators 12L, 12R, 13L, and 13R based on the equation of motion into which the identified dynamics parameters are substituted. This allows the device 30 to exert an effect according to the control method used, regardless of the subject's individual differences, physical condition, and other variable factors.

In addition, the control device 30 can control the drive units 12L, 12R, 13L, and 13R based on a motion equation into which the muscle torque (Tm) estimated by the joint circumference detection unit 40 is also substituted, so that the dynamics parameters can be identified even when the subject is generating muscle force, and the above-mentioned effects can be achieved without requiring the subject to wait for the dynamics parameters to be identified.

The gain between the bioelectric potential (BES) detected by the biosignal detection unit 41 and the muscle torque (Tm) detected by the joint detection unit 40 is adjusted to a preset gain (Gs), which can prevent situations in which the detection results from the biosignal detection unit 41 are insufficiently or excessively sensitive.

As a result, it is possible to prevent a situation in which the accuracy of identifying the subject's dynamic parameters is reduced, and also to prevent a situation in which the assisting forces generated by the drive units 12L, 12R, 13L, and 13R are too small or too large. Moreover, according to the movement function improving device 1 of this embodiment, calibration can be performed even when the subject is generating muscle force, and the subject does not need to wait for the calibration to be performed.

At least one of gravity compensation and inertia compensation using the dynamics parameters identified by the synthesis control unit 52 can be applied to the control device 30, which makes it possible to prevent situations in which the weight of the device itself becomes a burden on the subject, or in which the inertia of the device itself causes discomfort to the subject during operation.

In addition, the synthesis control unit 52 feedback-adjusts the synthesized control state while correcting the difference by the movement command from the brain and nervous system based on the bioautoregulation loop interactively promoted between the subject's body and the movement mechanism unit 2 so as to minimize the difference between the subject's movement intention and the movement phenomenon.

As a result, with the movement function improvement device 1, when the subject repeatedly performs voluntary movements using the movement mechanism unit 2, it becomes possible to improve the motor function of the subject's brain-nerve-muscle system by correcting the difference between the movement command from the brain-nerve system and the actual movement phenomenon.

Furthermore, in the motion function improvement device 1, when forming a bioautoregulation loop, the smallest motor control unit for realizing voluntary movements caused by the subject's will is set as a minimum voluntary motor control unit consisting of the brain nervous system, synaptic connections, and the muscular system, and a bioautoregulation loop is established for each minimum voluntary motor control unit that forms bodily movements that are linked to realize a motor phenomenon, using the motion mechanism section 2.

As a result, in the movement function improvement device 1, the minimum voluntary movement control unit is explicitly incorporated into the process of function improvement and treatment based on the basic theory of the biological self-control loop by the movement mechanism unit, which is influenced by the diseased area and disease cause. This has an effect on the other minimum voluntary movement control units, and they are linked in sync with the movement of the movement mechanism unit 2, and the functions of each minimum voluntary movement control unit are strengthened and adjusted in sync with the movement of the movement mechanism unit 2 to achieve the target movement, improving the function of the brain, nerves, and muscles.

For example, in subjects with progressive diseases (slowly progressive neuromuscular diseases), movement function would normally gradually decline over time, but by using the movement function improvement device 1, a previously unimaginable effect of function improvement was achieved, as shown in Figure 7. Also, while it is commonly believed that muscle destruction in everyday life and conventional exercise therapy increases blood CK levels, which are an indicator of muscle destruction in the blood, the movement function improvement device 1 has the effect of decreasing CK levels.

(4) Motion Function Improvement Device in Other Embodiments (4-1) Configuration of the Motion Mechanism (Waist Type: Hardware)
9(A) and (B) show a motion function improving device 100 including a waist-type motion mechanism unit 101 in another embodiment. Also, Fig. 10(A) and (B) show the main configuration of the motion mechanism unit 101 in Fig. 9 excluding the thigh cuff, belt, etc. The motion function improving device 100 is a device that assists the work and motion of a subject, and operates to detect bioelectric potential signals, the motion angle of the hip joint of the subject, and the absolute angle of the trunk, and apply a driving force from a driving unit based on the detection signals.

When a subject wearing the motion function improvement device 100 voluntarily lifts and carries a relatively heavy object, the bioelectric potential signals generated on the skin surface of the latissimus dorsi or gluteus maximus (gluteus maximus) and a driving torque corresponding to the motion angle of the subject's hip joint are applied as an assist force from the motion mechanism unit 101. Therefore, the subject can lift and carry the object using the combined force of his or her own muscle strength and the driving torque from the driving mechanism (actuator).

In addition to carrying tasks such as lifting an object and walking, the motion function improvement device 100 can also assist with ascending and descending tasks, such as when the subject goes up and down stairs while carrying luggage.

In the motion mechanism unit 101 of the motion function improving device 100, a waist frame 110 is attached to the back side of the subject's waist in the left-right direction. The waist frame 110 is a hollow member made of, for example, CFRP (carbon fiber reinforced plastic), and has a rounded shape that matches the shape of the back and both sides of the waist of the human body.

The waist frame 110 is configured to connect a first waist frame 110A, which is attached to the left and right sides of the back side of the subject's waist, and a second waist frame 110B, which is attached to the left and right sides above the first waist frame 110A, via a support 111.

The first waist frame 110A and the second waist frame 110B are attached to the waist of the subject by means of attachment belts 112, 113 that are placed around the abdomen of the subject. When attached, the first waist frame 110A and the second waist frame 110B are attached in a forward-leaning position so that both ends are lower than the back side, that is, so that both ends are located lower than the longitudinal center (the part located on the back side of the subject).

A left side frame 120 and a right side frame 121 are fixed to both ends of the first waist frame 110A and the second waist frame 110B.

In addition, on the outside opposite the side where the operating mechanism unit 101 is attached, a battery 122 is removably stored in the center of the first waist frame 110A, and wiring etc. connected to the battery 122 are inserted into the internal space.

The pillar 111 is a member that vertically connects the longitudinal center of the first waist frame 110A and the longitudinal center of the second waist frame 110B. The pillar 111 is, for example, a hollow member made of reinforced resin, and sensor wiring is inserted inside. In addition, a control device (not shown, but equivalent to the control device 30 in Figure 5 described above) that controls the operation of the operating mechanism unit 101 is provided inside the pillar 111.

The strength of the monocoque structure is ensured by the support pillars 111, which hold the various components constituting the first waist frame 110A and the second waist frame 110B so that they do not rotate. In addition, the support pillars 111 are respectively fitted with a wearing belt 112 corresponding to the first waist frame 110A and a wearing belt 113 corresponding to the second waist frame 110B.

The left side frame 120 is fixed to the left of the subject's hip joint by joining the left end of the first waist frame 110A to the left end of the second waist frame 110B. The right side frame 121 has a structure that is roughly symmetrical to the left side frame 120, and is fixed to the right end of the first waist frame 110A to the right end of the second waist frame 110B by joining them.

The left side frame 120 has an actuator and a brake mechanism (both not shown) built in, and is provided with a minus button 123 for inputting to reduce the driving force of the actuator. This minus button 123 lights up when the power of the motion function improvement device is on.

The right side frame 121 has an actuator and a brake mechanism (neither shown), and is provided with a plus button 124 for inputting to increase the driving force of the actuator, and a power button 125 for switching the power of the motion function improving device 1 on and off. The plus button 124 and the power button 125 are lit when the power of the motion function improving device is on.

In this way, the lumbar frames (first lumbar frame 110A and second lumbar frame 110B), support pillars 111, and side frames (left side frame 120 and right side frame 121) are assembled into a single unit, creating a monocoque structure in which the frame itself bears the stress.

In Figures 9(A) and (B), the thigh fixing section 130 consists of a left thigh fixing section 130L that fixes the subject's left thigh, and a right thigh fixing section 130R that fixes the subject's right thigh.

The left thigh fixing part 130L is composed of a stay part 131L connected to an actuator in the left side frame 120 and a belt part 132L attached to the stay part 131L, and is rotatable relative to the left side frame 120 in a side view.

The right thigh fixing part 130R is composed of a stay part 131R connected to an actuator inside the right side frame 121 and a belt part 132R attached to the stay part 131R, and is rotatable relative to the right side frame 121 in a side view.

In addition, in the left thigh fixing section 130L and the right thigh fixing section 130R, the stay sections 131L, 131R are designed to be the optimal length based on the average length of the human thigh, and the subject's thighs are fixed by the belt sections 132L, 132R.

The attachment belt 112 is a belt that is placed across the abdominal side when attaching the first waist frame 110A to the subject, and serves as the main means for attaching the operating mechanism unit 101 to the waist of the human body.

The attachment belt 113 is a belt that is placed on the abdominal side when attaching the second waist frame 110B to the subject. The attachment belt 113 is used to secure the operating mechanism unit 101 to the human body above the attachment belt 113 in order to efficiently transmit the reaction force generated by the movement of the legs to the abdomen or waist of the subject when the subject wearing the operating mechanism unit 101 lifts a relatively heavy object with bent knees.

The battery 122 is provided on the outside of the center of the first waist frame 110A, on the outside opposite to the side where the operating mechanism unit 101 is attached, and supplies power to the control device, actuator, brake mechanism (not shown), minus button 123, plus button 124, and power button 125.

The biosignal detection unit 140, which has a bioelectric potential sensor, is attached to the back of the subject's waist and detects bioelectric potential signals associated with muscle activity when the subject tries to raise the trunk or muscle activity when the subject tries to maintain the angle of the trunk.

The bioelectric potential sensors of the biosignal detection unit 140 are connected to the ends of wires that extend from holes provided in the support 111 to the outside of the support, and three of them are provided. The bioelectric potential sensors are attached to the back of the subject's waist to detect bioelectric potential signals generated when the subject moves their trunk muscles.

The biopotential signal detected by the biosignal detection unit 140 is input to the control device. The biopotential sensor may be attached to the subject's back using tape or gel. One of the three sensors is used to measure the reference signal, and the remaining two sensors are used to measure the biopotential signal.

In fact, in the motion function improving device 100, the motion mechanism unit 101 is attached to the back side of the subject's waist. The motion function improving device 100 is a device that generates an assisting force (assisting force) to assist the movement of the thighs relative to the waist when the subject stands up as shown in FIG. 11(B) from a bent position (squatting position) as shown in FIG. 11(A). Such motions of the subject include, for example, the motion of standing up from a squatting position, the motion of lifting an object from a squatting position, the motion of assisting transfer, etc.

Figure 11(C) is a diagram (left side view) showing the movable range of the movement mechanism unit 101 in the movement function improving device 100. The left thigh fixing unit 130L can rotate 130° clockwise and 30° counterclockwise from the reference position shown in Figure 11(C) with the left side frame 120 as the center of rotation. With such movement, the movement function improving device generates an assist force to assist the movement of the thigh relative to the waist when the subject stands up as shown in Figure 11(B) from a bent position as shown in Figure 11(A). The movement range of the right thigh fixing unit 130R is the same.

In this embodiment, the waist-type motion function improving device 100 has a configuration (excluding the receiver 65) that is almost identical to the control system 3 of the lower limb-type motion mechanism improving device 1 described above. As a result, the motion function improving device 100 also has functionally a voluntary control step for making the subject move in accordance with his/her motion intention, an autonomous control step for generating a preset ideal power, and an impedance control step (including gravity compensation control) for reducing the feeling of difficulty in moving due to the load and viscous friction of the motion mechanism unit 101 itself.

As a result, with the waist-type movement function improvement device 100, the subject feels as if the movement mechanism unit 101 is a part of his or her body, making it possible to achieve functional fusion and integration between the subject and the movement mechanism unit 101.

In fact, with the motion function improving device 100, when the subject stands up from a bent position as shown in FIG. 11(A) to a position as shown in FIG. 11(B), an assist force can be generated to assist the movement of the thighs relative to the waist. Such an assist force is generated by driving a drive unit (actuator) based on a bioelectric potential signal detected by the biosignal detection unit 140, which is associated with muscle activity when the subject tries to raise the trunk or muscle activity when trying to maintain the angle of the trunk.

Therefore, it is possible to provide a highly convenient movement function improving device 100 that can provide the necessary assistive force in the necessary direction according to the will of the subject. It is also possible to provide a movement function improving device 100 that can minimize the power (muscle force) that the subject must generate himself, and can prevent situations that impair the subject's convenience.

If the control device determines that the signal levels of the biological signals from the left and right thighs of the subject are not equal, it determines that the subject is walking, but if it determines that the signal levels are equal, it determines that the subject is stationary.

In addition, when the control device determines that the subject is in a stopped state, if it determines that both the left and right hip joint angles are greater than a specified angle, it determines that the subject is walking, but if it determines that they are equal to or less than the specified angle, it determines that the subject is in a posture with their upper body lowered forward.

Furthermore, in the motion function improvement device 100, the synthesis control step that synthesizes the control states from the voluntary control step and the autonomous control step so as to obtain a control ratio according to the phase of the task not only executes the impedance control step described above, but also feedback-adjusts the synthesized control state while simultaneously correcting the difference by the motion command from the brain and nervous system based on the bioautoregulation loop that is interactively promoted between the subject's body and the motion mechanism so as to minimize the difference between the subject's motion intention and the motor phenomenon.

As a result, in the movement function improvement device 100, when the subject repeatedly performs voluntary movements using the movement mechanism unit 101, it becomes possible to improve the motor function of the subject's brain-nerve-muscle system by correcting the difference between the movement command from the brain-nerve system and the actual movement phenomenon.

Furthermore, in the movement function improvement device 100, when forming a bioautoregulation loop, the smallest movement control unit for realizing voluntary movements caused by the subject's will is set as a minimum voluntary movement control unit consisting of the brain nervous system, synaptic connections, and the muscular system, and a bioautoregulation loop is established for each minimum voluntary movement control unit that forms bodily movements that are linked to realize a movement phenomenon, using the movement mechanism section 101.

As a result, in the movement function improvement device 100, the minimum voluntary movement control unit is explicitly incorporated into the process of function improvement and treatment based on the basic theory of the biological self-control loop by the movement mechanism unit, which is influenced by the diseased area and disease cause. This has an effect on the other minimum voluntary movement control units, and they are linked in sync with the movement of the movement mechanism unit 101, and the functions of each minimum voluntary movement control unit are strengthened and adjusted in sync with the movement of the movement mechanism unit to achieve the target movement, thereby improving the function of the brain, nerves, and muscles.

(3-2) Configuration of the movement mechanism (single-joint type: hardware)
12 shows a motion function improving device 150 including a single-joint type motion mechanism unit 151 according to another embodiment. The main components of the motion mechanism unit 151 in this motion function improving device 150, excluding the cuff, belt, etc., are shown.

The movement function improvement device 150 is a device that supports (assists) the movement of a movement mechanism unit 151 attached to a joint part (elbow joint, knee joint, etc.) of the subject's upper limbs or lower limbs, and has the function of improving the smoothness of upper limb or lower limb movement by driving a drive unit (actuator) in accordance with the subject's intention to move, assisting voluntary movement, and performing repeated joint extension movements.

As shown in FIG. 12, the motion function improving device 150 according to this embodiment is composed of a motion mechanism section 151 that is attached to any joint of the subject, a control unit 152 that has a built-in control device (not shown, but equivalent to the control device 30 in FIG. 5 described above), and an operation section 153 that displays necessary information and allows the user to change or confirm settings. Note that the electrode cable and charger connected to the control unit 152 are omitted from FIG. 12.

The operating mechanism 151 is configured to rotate the first transmission member 170 and the second transmission member 171 relative to one another using the driving force of the drive unit (actuator) 160. The first transmission member 170 and the second transmission member 171 are attachments selected according to the joint of the subject, and are fastened to one end portion and the other end portion of the joint via the first coupling portion 175 and the second coupling portion 176, respectively.

The drive unit 160 is positioned to the side of the knee joint of the subject, and has a first motor housing 180 that houses either the rotor (magnet) or the stator (coil), and a second motor housing 181 that houses the other of the rotor (magnet) or the stator (coil).

The first motor housing 180 is provided with a first coupling portion to which a first transmission member attached to one end portion of the joint of the subject (e.g., the thigh) is coupled. The second motor housing 181 is provided with a second coupling portion 38 to which a second transmission member 50 attached to the other end portion of the joint (e.g., the shin) is coupled. Furthermore, the first transmission member 40 has a pair of cuffs (not shown) fixed by fixing members 76 to be fitted to one end portion of the joint of the subject.

The drive unit 160 is configured by stacking a first motor housing 180 and a second motor housing 181 on the same axis, with the back surface of the first motor housing 180 and the back surface of the second motor housing 181 facing each other. The center of rotation of the first motor housing 180 and the center of rotation of the second motor housing 181 are connected by a motor shaft (not shown) mounted between the housings.

The first motor housing 180 further has a circular cover 180A formed in a circular dome shape and an extension portion 180B formed extending radially from the outer periphery of the circular cover 180A. The end of the extension portion 180B is formed to support the first coupling portion 175 and to guide the insertion and removal operation of the first transmission member 170. Similarly, the second motor housing 181 has a circular cover 181A formed in a circular dome shape and an extension portion 181B formed extending radially from the outer periphery of the circular cover 181A. The end of the extension portion 181B is formed to support the second coupling portion 176 and to guide the insertion and removal operation of the second transmission member 171.

In the drive unit 160, the relative rotation angle θ between the first motor housing 180 and the second motor housing 181 is set to, for example, θ = 65 degrees to 180 degrees according to the range of motion of the knee joint. Furthermore, when the relative rotation angle θ reaches a minimum angle θmin = 65 degrees and a maximum angle θmax = 180 degrees, a stopper between the first motor housing 180 and the second motor housing 181 comes into contact, restricting the relative rotation.

The drive unit 161 further includes an angle sensor that detects the relative rotation angle θ between the first motor housing 180 and the second motor housing 181. This angle sensor is housed inside either the first motor housing 180 or the second motor housing 181.

The single-joint type motion function improving device 150 in this embodiment has a configuration (excluding the receiving unit) that is almost identical to the control system 3 of the lower limb type motion mechanism improving device 1 described above. As a result, the motion function improving device 150 also has functionally a voluntary control step for moving in accordance with the subject's motion intention, an autonomous control step for generating a preset ideal power, and an impedance control step (including gravity compensation control) for reducing the feeling of difficulty in movement due to the load and viscous friction of the motion mechanism unit 151 itself.

As a result, with the single-joint type motion function improvement device 150, the subject feels as if the motion mechanism unit 151 is a part of his or her body, making it possible to achieve functional fusion and integration between the subject and the motion mechanism unit 151.

Actually, with the motion function improving device 150, as shown in FIG. 13, by attaching the motion mechanism unit 151 to the knee joint of the subject's right leg, it is possible to perform functional recovery training (rehabilitation) after treatment or surgery on the subject's right knee joint. In addition, since functional recovery training can be performed using the motion function improving device 150 even when the subject is lying in bed or sitting in a chair, it is possible to perform functional recovery training appropriately without placing undue strain on the subject.

In addition, with the movement function improvement device 150, as shown in FIG. 14, by attaching the movement mechanism unit 151 to the elbow joint of the subject's left arm, it is possible to carry out functional recovery training (rehabilitation) after treatment or surgery on the subject's left elbow joint.

Furthermore, in the motion function improvement device 150, the synthesis control step that synthesizes the control states from the voluntary control step and the autonomous control step so as to obtain a control ratio according to the phase of the task not only executes the impedance control step described above, but also feedback-adjusts the synthesized control state while simultaneously correcting the difference by the motion command from the brain and nervous system based on the bioautoregulation loop interactively promoted between the subject's body and the motion mechanism unit 151 so as to minimize the difference between the subject's motion intention and the motor phenomenon.

As a result, in the movement function improving device 150, when the subject repeatedly performs voluntary movements using the movement mechanism unit 151, it becomes possible to improve the motor function of the subject's brain-nerve-muscle system by correcting the difference between the movement command from the brain-nerve system and the actual movement phenomenon.

Furthermore, in the movement function improvement device 150, when forming a bioautonomic control loop, the smallest movement control unit for realizing voluntary movements caused by the subject's will is set as a minimum voluntary movement control unit consisting of the brain nervous system, synaptic connections, and muscular system, and a bioautonomic control loop is established for each minimum voluntary movement control unit that forms bodily movements that are linked to realize a movement phenomenon, using the movement mechanism section 151.

As a result, in the movement function improvement device 150, the minimum voluntary movement control unit is explicitly incorporated into the process of function improvement and treatment based on the basic theory of the bioautoregulation loop by the movement mechanism unit 151, which is influenced by the diseased area and disease cause, so that the influence is extended to other minimum voluntary movement control units, and linkage progresses in synchronization with the operation of the movement mechanism unit 151, and the function of each minimum voluntary movement control unit is strengthened and adjusted in synchronization with the operation of the movement mechanism unit 151 to achieve the target movement, thereby improving the function of the brain, nerves, and muscles.

(5) Other embodiments As described above, in this embodiment, the movement function improvement devices 1, 100, 150 are described as having a movement mechanism unit 2 for the lower body (lower limb type), a waist-type movement mechanism unit 101, and even a single-joint type movement mechanism unit 151. However, the present invention is not limited to this, and can be widely applied to movement function improvement devices having a movement mechanism unit adapted to any joint part that is capable of physical movement of the subject.

For example, a movement function improving device may be configured that includes a hand-type movement mechanism and a control system that has the functional configuration of the basic theory of the voluntary control step, autonomous control step, impedance control step, and bioautonomous control loop described above. This hand-type movement mechanism may be configured to be directly attached to the subject's fingers, or may be configured to be fixed to a tabletop.

In the above embodiment, the joint detection unit 40 detects the absolute angle, rotation angle, angular velocity, angular acceleration, and drive torque between the rotor frame and the stator frame of the drive units 12L, 12R, 13L, and 13R (160) in the operating mechanism unit 2 (101, 151) as physical quantities around the joints. However, the present invention is not limited to this. It is also possible to detect the results of parameter identification of at least one of the generated muscle force generated in the musculoskeletal system, the range of motion, movement speed, and reaction speed of each joint, the autonomous control characteristics against disturbances, the moment of inertia, mass, and center of gravity of the frame, the impedance adjustment results of the joint system including the flexor and extensor muscles (viscosity characteristics due to friction), electrical physical quantities (command signals), and the like as physical quantities around the joints.

1, 100, 150...movement function improvement device, 2, 101, 151...movement mechanism unit, 3...control system, 12L, 12R, 13L, 13R, 160...drive unit, 26L, 26R...dedicated shoes, 30...control device, 31...data storage unit, 32...potentiometer, 33...absolute angle sensor, 34...torque sensor, 40...joint circumference detection unit, 41, 140...biological signal detection unit, 50...optional control unit, 51...autonomous control unit, 52...synthesis control unit, 55...current control unit, 60...FRF sensor, 70...relative force detection unit, 71...joint torque estimation unit, 72...muscle torque estimation unit.

Claims (8)

An operating mechanism unit that is used to be integrated with a subject and has a drive unit that actively or passively drives in conjunction with the subject's body movement;
a signal detection unit that detects a change in an ionic current transmitted from the subject's nervous system to the subject's muscular system as a bioelectric potential signal appearing on the skin surface;
a joint surrounding detection unit that detects a physical quantity around the joint associated with a body movement of the subject based on an output signal from the drive unit;
An optional control unit that controls the drive unit based on the bioelectric potential signal and a physical quantity around the joint so as to produce a movement phenomenon that reflects the subject's intention to move;
an autonomous control unit that stores in a data storage unit reference parameters for each phase, which is a series of minimum movement units constituting a movement pattern of the subject classified as a task, and estimates a phase of the task of the subject by comparing a physical quantity around the joint with the reference parameters stored in the data storage unit, and controls the drive unit to generate a power corresponding to the phase;
a synthesis control unit that stores a control ratio of the voluntary control unit and the autonomous control unit set for each phase of each task in the data storage unit, and synthesizes the control states by the voluntary control unit and the autonomous control unit so as to obtain a control ratio corresponding to the phase;
The synthesis control unit is
Compensating the physical impedance of the entire system consisting of the entire apparatus and the subject based on the physical quantity around the joint in accordance with the physical characteristics of the entire system including the human body characteristics of the subject and gravity;
A device for improving movement function, characterized in that, based on a bioautoregulation loop interactively promoted between the subject's body and the movement mechanism, the difference between the subject's movement intention and the motor phenomenon is minimized, and at the same time, the difference is corrected by movement commands from the nervous system, and the synthesized control state is feedback-adjusted. A center-of-gravity position detection unit that detects a center-of-gravity position of the subject based on a change in load on the sole of the subject's foot;
a walking state recognition unit that recognizes a walking state of the subject based on a control state by the synthesis control unit and a center of gravity position by the center of gravity position detection unit,
The movement function improving device according to claim 1, characterized in that the voluntary control unit controls the drive unit based on the bioelectric potential signal, physical quantities around the joints, and the walking state recognized by the walking state recognition unit, so as to produce a movement phenomenon that reflects the subject's movement intention. When forming the biological self-control loop, a minimum motor control unit for realizing a voluntary movement caused by the will of the subject is set as a minimum voluntary movement control unit consisting of a cranial nervous system, synaptic connections, and a muscular system;
The device for improving movement function according to claim 1 or 2, characterized in that the movement mechanism section is used to establish the biofeedback loop for each of the minimum voluntary movement control units that form coordinated body movements to realize the movement phenomenon. The motion function improving device according to claim 1 or 2, characterized in that the joint surrounding detection unit detects, as physical quantities around the joint, an absolute angle between a rotor side frame and a stator side frame of the drive unit in the motion support device, a rotation angle, an angular velocity, an angular acceleration, and a drive torque. In a state where an operating mechanism unit having a drive unit that actively or passively drives in conjunction with a body movement of a subject is used in such a manner as to be integrated with the subject,
an optional control step of controlling the driving unit based on a bioelectric potential signal appearing on the skin surface representing a change in ionic current transmitted from the subject's nervous system to the muscular system, and on a physical quantity around the joints associated with the subject's physical movement detected based on an output signal from the driving unit, so as to produce a movement phenomenon that reflects the subject's intention to move;
an autonomous control step of storing in a data storage unit reference parameters for each phase, which is a series of minimum movement units constituting a movement pattern of the subject classified as a task, and estimating a phase of the task of the subject by comparing a physical quantity around the joint with the reference parameters stored in the data storage unit, and controlling the drive unit to generate a power corresponding to the phase;
a synthesis control step of storing a control ratio of the optional control step and the autonomous control step set for each phase of each task in the data storage unit, and synthesizing a control state by the optional control step and the autonomous control step so as to obtain a control ratio corresponding to the phase;
In the synthesis control step,
Compensating the physical impedance of the entire system consisting of the entire apparatus and the subject based on the physical quantity around the joint in accordance with the physical characteristics of the entire system including the human body characteristics of the subject and gravity;
A method for improving movement function, comprising: based on a bioautoregulation loop interactively promoted between the subject's body and the movement mechanism, correcting the difference by movement commands from the nervous system while simultaneously feedback-adjusting the synthesized control state so as to minimize the difference between the subject's movement intention and the motor phenomenon. a walking state recognition step of recognizing a walking state of the subject based on a control state by the synthesis control step and a center of gravity position of the subject detected based on a load change on the sole of the subject,
The method for improving movement function according to claim 4, characterized in that in the voluntary control step, the drive unit is controlled so as to produce a movement phenomenon that reflects the subject's movement intention based on the bioelectric potential signal, physical quantities around the joint, and the walking state recognized in the walking state recognition step. When forming the biological self-control loop, a minimum motor control unit for realizing a voluntary movement caused by the will of the subject is set as a minimum voluntary movement control unit consisting of a brain nervous system, synaptic connections, and a muscular system;
The method for improving movement function according to claim 5 or 6, characterized in that the movement mechanism section is used to establish the bioautonomic control loop for each of the minimum voluntary movement control units that form a body movement that is linked to realize the movement phenomenon. The method for improving movement function according to claim 5 or 6, characterized in that the physical quantities around the joint are detected by detecting an absolute angle between a frame on a rotor side and a frame on a stator side of the drive unit in the movement assistance device, a rotation angle, an angular velocity, an angular acceleration, and a drive torque.

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