Body weight support type walking assistance device and its operation method

Abstract

To propose a body weight support type walking assist device capable of assisting in a motion while significantly reducing a weight load due to a body weight of a wearer to a knee joint part even in a walking motion leg supporting period.SOLUTION: When a wearer wearing a body weight support type walking assist device performs a walking motion in a state where his / her hip is supported by a seat part, bending of a knee joint part of the wearer is restricted to a predetermined range in transition from a leg free period to a leg supporting period of the walking motion, and on the other hand, bending or extension of the knee joint part of the wearer is enabled, and power according to the intension of the wearer is imparted in transition from the leg supporting period to the leg free period.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a body weight support type walking assistance device and a control method thereof, and is particularly suitable for application to a body weight support type walking assistance device and a control method thereof for patients with knee osteoarthritis. [Background technology]

[0002] In recent years, Japan has become an aging society, and degenerative diseases based on age-related changes have been steadily increasing, with osteoarthritis becoming one of the most common orthopedic diseases. Of these, knee osteoarthritis is mainly caused by wear and tear of knee cartilage due to aging, causing symptoms such as pain, inflammation, and contracture of the knee joint, and gradually progressing deformation of the knee joint leads to walking difficulties, significantly reducing quality of life (QOL).

[0003] Although correcting deformities is said to be effective in slowing or improving the progression of knee osteoarthritis, it is often not possible to achieve sufficient self-healing, and ultimately surgery is required. However, surgical procedures such as high tibial osteotomy and artificial joint replacement involve significant risks of complications and significant mental and physical burdens, so the development of new non-invasive techniques is needed.

[0004] In recent years, advances have been made in regenerative medicine, in which cultured tissue made from human cells is transplanted into the affected area. For patients suffering from knee osteoarthritis, it is possible to treat them by injecting stem cells or other materials from the outside into the internal space of the knee joint, thereby regenerating cartilage cells.

[0005] The present invention proposes a knee joint orthotic manufacturing device and a knee joint orthotic manufacturing method that can promote natural treatment or regenerative cell therapy non-invasively in daily life after performing such regenerative medical treatment on the knee joint (see Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2018 / 051898 Summary of the Invention [Problem to be solved by the invention]

[0007] After chondrocytes are transplanted into the knee joint, it is necessary to reduce the load on the knee joint until the cartilage in the damaged knee joint is integrated with the transplanted cartilage. In particular, since the patient's own weight is placed on the knee joint, it is desirable to minimize the weight on the knee joint when the patient walks after treatment.

[0008] The present invention has been made in consideration of the above points, and proposes a weight-supported walking assistance device and a control method thereof that can assist the wearer in walking while significantly reducing the weight burden on the knee joint. [Means for solving the problem]

[0009] In order to solve this problem, the body weight supported walking assist device of the present invention comprises a seat section that supports the buttocks of the wearer, a thigh frame and a lower leg frame that are arranged along the inside of the wearer's leg, a hip joint connecting section that connects the underside of the seat section to one end of the thigh frame and is rotatable in accordance with movement of the wearer's hip joint, a rotation drive section that is provided at the hip joint connecting section and drives the thigh frame in the rotational direction of the hip joint relative to the seat section, a knee joint connecting section that connects the other end of the thigh frame to one end of the lower leg frame and is rotatable in accordance with movement of the wearer's knee joint, a locking mechanism section that fixes or releases the rotational state of the knee joint connecting section, shoe sections that are attached to the left and right feet of the wearer, one of which is joined to the other end of the lower leg frame, and shoe sections that are attached to the left and right shoe sections, respectively, and that fit the soles of the wearer's feet. The device is equipped with a floor reaction force sensor that detects pressure distribution, a bio-signal detection unit that is attached to the wearer's thigh on the thigh frame placement side and detects bio-signals resulting from the wearer's walking movement, a walking synchronization calculation unit that calculates the wearer's walking cycle based on the detection results of the floor reaction force sensor, and a control unit that fixes the rotational state of the locking mechanism unit in the bending direction at the time of transition from the swing leg phase to the supporting leg phase of the walking movement so as to limit the flexion of the wearer's knee joint to a predetermined range based on the calculation results of the walking synchronization calculation unit, and releases the locking mechanism unit at the time of transition from the supporting leg phase to the swing leg phase so that the wearer's knee joint can be flexed or extended, and the control unit generates power in the rotation drive unit in accordance with the wearer's intention at the time of transition from the supporting leg phase to the swing leg phase based on the detection results of the bio-signal detection unit.

[0010] In this way, when a wearer wearing a body weight supported walking assist device walks with their buttocks supported on the seat, the flexion of the wearer's knee joint is limited to a predetermined range when transitioning from the swing phase to the supporting phase of the walking movement, while at the same time the wearer's knee joint can be flexed or extended when transitioning from the supporting phase to the swing phase, and power is applied in accordance with the wearer's will, thereby reducing the floor reaction force during the supporting phase of the walking movement and reducing the load on the knee joint due to the wearer's own weight, thereby assisted movement.

[0011] In addition, in the present invention, the control unit adjusts the fixed range of the rotational state of the locking mechanism unit so that the load on the wearer's knee joint increases in accordance with the transition state toward correction aimed at improving symptoms of the wearer's knee joint.

[0012] As a result, the wearer can adjust the slight bending state of the knee joint to support the body weight during the supporting leg phase of walking, thereby reducing the weight burden on the knee joint while optimizing it.

[0013] Furthermore, the present invention further comprises a seat reaction force sensor mounted on the seat portion that detects the pressure distribution on the wearer's buttocks, and the control portion controls the rotation drive portion based on the detection results of the biological signal detection portion and the seat reaction force sensor so that the shoe portion does not come into contact with the walking surface during the swing phase of walking motion.

[0014] As a result, the body weight-supported walking assistance device reduces the floor reaction force during the supporting leg phase of walking based on the pressure distribution not only on the soles of the wearer's feet but also on the pressure distribution on the wearer's buttocks, and can assist movement while adjusting with high precision the weight burden on the knee joint caused by the wearer's own weight to an optimal state.

[0015] Furthermore, in the control method for the body weight supported walking assist device of the present invention, the buttocks of the wearer are supported by the seat, while the thigh frame and the lower leg frame are arranged along the inside of the wearer's legs, and shoe parts, one of which is joined to the other end of the lower leg frame, are worn on the left and right feet of the wearer, and the hip joint connecting part that connects the underside of the seat to one end of the thigh frame is made rotatable in accordance with the movement of the wearer's hip joint, and the knee joint connecting part that connects the other end of the thigh frame to one end of the lower leg frame is made rotatable in accordance with the movement of the wearer's knee joint, a rotation drive part is provided on the hip joint connecting part that drives the thigh frame in the rotation direction of the hip joint relative to the seat, and a lock mechanism part is provided to fix or release the rotation state of the knee joint connecting part, and the left and right shoe parts are fitted to the soles of the wearer's feet. The device comprises a first step of detecting pressure distribution; a second step of calculating the walking cycle of the wearer based on the detection result of the first step; a third step of fixing the rotational state of the locking mechanism in the bending direction so as to limit the bending of the wearer's knee joint to a predetermined range when transitioning from the swing phase to the supporting phase of the walking motion based on the calculation result of the second step, while releasing the locking mechanism when transitioning from the supporting phase to the swing phase so as to allow the wearer's knee joint to bend or extend; a fourth step of detecting a biological signal resulting from the walking motion of the wearer in the thigh on the thigh frame arrangement side; and a fifth step of generating power in the rotation drive unit according to the wearer's intention when transitioning from the supporting phase to the swing phase in the third step based on the detection result of the fourth step.

[0016] In this way, when a wearer wearing a body weight supported walking assist device walks with their buttocks supported on the seat, the flexion of the wearer's knee joint is limited to a predetermined range when transitioning from the swing phase to the supporting phase of the walking movement, while at the same time the wearer's knee joint can be flexed or extended when transitioning from the supporting phase to the swing phase, and power is applied in accordance with the wearer's will, thereby reducing the floor reaction force during the supporting phase of the walking movement and reducing the load on the knee joint due to the wearer's own weight, thereby assisted movement. [Effects of the Invention]

[0017] As described above, according to the present invention, it is possible to realize a weight-supported walking assistance device and a control method thereof that can assist the wearer in walking while significantly reducing the weight burden on the knee joint. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a conceptual diagram showing the configuration of a body weight-supported walking assistance device according to an embodiment of the present invention. [Figure 2] 2 is an exploded view showing the configuration of a drive unit of the body weight support type walking assistance device shown in FIG. 1. FIG. [Figure 3] FIG. 2 is a perspective view showing the external configuration of the knee joint connecting portion shown in FIG. [Figure 4] FIG. 2 is a block diagram showing the configuration of a control system of the body weight support type walking assistance device shown in FIG. [Figure 5] 4 is a schematic diagram illustrating the operating state of the knee joint connecting portion shown in FIG. 3. [Figure 6] 1 is a schematic diagram illustrating a walking motion of a wearer wearing a body weight support type walking assistance device; [Figure 7] 1 is a schematic diagram illustrating a walking motion of a wearer wearing a body weight support type walking assistance device; [Figure 8] 1 is a schematic diagram illustrating a walking motion of a wearer wearing a body weight support type walking assistance device; [Figure 9] 10 is a graph and a table illustrating a body weight support function. [Figure 10] 10 is a graph and a table illustrating a body weight support function. [Figure 11] 10 is a graph and a table illustrating a body weight support function. [Figure 12] FIG. 10 is a conceptual diagram showing the configuration of a body weight-supported walking assistance device according to another embodiment. [Figure 13] 13 is a conceptual diagram showing the external configuration and internal structure of the knee joint connecting portion shown in FIG. 12. FIG. [Figure 14] FIG. 13 is a conceptual diagram showing the internal structure of the knee joint connecting portion shown in FIG. [Figure 15] FIG. 13 is a conceptual diagram showing the internal structure of the knee joint connecting portion shown in FIG. [Figure 16] 10 is a graph and a table illustrating a body weight support function. [Figure 17] 10 is a graph and a table illustrating a body weight support function. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described in detail below with reference to the drawings.

[0020] (1) Configuration of the body weight support type walking assistance device according to the present invention FIG. 1 shows a body weight-supported walking assistance device 1 in this embodiment, which comprises a seat 2 that supports the wearer's buttocks, a thigh frame 3 and a lower leg frame 4 that are arranged along the inside of the wearer's legs, and shoe parts 5 that are attached to the wearer's left and right feet, one of which is joined to the other end 4B of the lower leg frame 4.

[0021] The thigh frame 3 and the lower leg frame 4 have a frame body formed in the shape of a long, thin plate made of metal such as stainless steel or carbon fiber, and are lightweight and highly rigid.

[0022] A hip joint connector 10 that can rotate in response to the movement of the hip joint of the wearer is connected between a seat clamp 2A fixed to the underside of the seat portion 2 and one end 3A of the thigh frame 3. This hip joint connector 10 has a drive unit (rotation drive unit) 20 that drives the thigh frame 3 relative to the seat portion 2 in the rotation direction of the hip joint.

[0023] 2, the drive unit 20 has a flat actuator 21 made up of, for example, a brushless DC motor, an actuator control unit 22 that drives and controls the actuator 21, and a reducer 23 that converts the rotation speed of the rotor of the actuator 21 to a predetermined reduction ratio and outputs the converted speed. The actuator control unit 22 has a built-in MCM (Multi-Chip Module) equipped with a CPU (Central Processing Unit), memory, etc.

[0024] The operation unit 25 consists of a touch panel 25A that forms the surface of the housing and a power button 25B in the center of the housing. The operation content on the touch panel 25A by the wearer's fingertip is reflected in the actuator control unit 22 as the detection result of the touch sensor 24, and the power is turned on or off in response to pressing the power button 25B.

[0025] The drive unit 20 has the main body of the reducer 23 and the actuator control unit 22 stored in approximately the same plane in the seat clamp 2A fixed to the underside of the seat 2, and the output shaft of the reducer 23 is fixed to one end 3A of the thigh frame 3.

[0026] Furthermore, a knee joint connecting part 30 is connected between the other end 3B of the thigh frame 3 and one end 4A of the lower leg frame 4, and is rotatable in accordance with the movement of the knee joint of the wearer.

[0027] This knee joint connecting section 30 has a closed-loop structure consisting of a four-link mechanism consisting of a fixed link, a driving link, a driven link, and an intermediate link, and the driven link rotates via the intermediate link in response to the rotation of the driving link based on the fixed link.

[0028] As shown in Figures 3(A) and (B), thigh-side link 31, which is connected to the other end 3B of thigh frame 3, has rotation axes R1 and R2 at the center and rear end, respectively, to form a fixed joint. One end 32A of bending link 32, which serves as a driving joint, is connected to rear rotation axis R1, and one end 33A of patella link 33, which serves as a driven joint, is connected to central rotation axis R2.

[0029] The crus side link part 34, which is connected to one end 4A of the crus frame 4, has rotation axes R3 and R4 on the front and rear sides, respectively, to form an intermediate section, and the other end 33B of the patella link part 33 is connected to the front rotation axis R3, and the other end 32B of the bending link part 32 is connected to the rear rotation axis R4.

[0030] In the knee joint connection section 30, a locking mechanism section 35 is provided at the connection point between one end 4A of the lower leg frame 4 and the other end 32B of the bending link section 32, with the corresponding rotation axis R5 as its center, and is designed to fix or release the rotational state of the lower leg frame 4 and the bending link section 32 depending on the operation of the electromagnetic solenoid.

[0031] The thigh frame 3 and the lower leg frame 4 each have a built-in adjustment mechanism (not shown) that allows the frame length to be freely adjusted.

[0032] 1, a shoe part 5 to be worn on the wearer's foot to be treated is attached to the other end 4B of the lower leg frame 4. The shoe part 5 has a low boot that encases the wearer's foot and a fixed fastening part (not shown) made of a relatively rigid metal member attached to the inside surface of the low boot.

[0033] Cuffs 7 and 8 are attached to the thigh frame 3 and the lower leg frame 4, respectively (Fig. 1), and are designed to be wrapped around the thigh and lower leg of the wearer and securely fastened.

[0034] In this way, with the weight-supported walking assistance device 1, when the wearer walks with their buttocks supported on the seat 2, it is possible to reduce the load on the knee joint caused by the wearer's own weight during the supporting leg phase of the walking movement.

[0035] (2) Internal system configuration of the body weight support walking assist device 4 shows the configuration of the control system of the body weight supported walking assistance device 1 according to this embodiment. The control system has a control unit 40 that performs overall control of the entire system, and a data storage unit 41.

[0036] An insole-type floor reaction force sensor 42 is provided on the sole of each shoe part 5, and detects the reaction force (pressure distribution on the sole) to the load applied to the sole of the wearer's foot. This floor reaction force sensor 42 can measure the load applied to the sole of the foot separately for the forefoot part (toe part) and the rearfoot part (heel part) independently.

[0037] This floor reaction force sensor 42 consists 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 shift and whether or not the wearer's legs are in contact with the ground.

[0038] In addition to the shoe structure, the shoe section 5 has a floor reaction force sensor 42 and a floor reaction force control section 43 consisting of an MCU (Micro Control Unit). The output of the floor reaction force sensor 42 is converted into a voltage via a converter 44, and then input to the floor reaction force control section 43 after high frequency bands are cut off via an LPF (Low Pass Filter) 45.

[0039] Based on the detection results of the floor reaction force sensor 42, the floor reaction force control unit 43 determines whether or not the wearer has made contact with the ground and any changes in load due to the shift in weight of the wearer, and sends this as floor reaction force data to the control unit 40. The control unit 40 stores the received floor reaction force data in the reference parameter database of the data storage unit 41.

[0040] The control unit 40, which functions as a walking synchronization calculation unit, calculates the walking cycle of the wearer based on the detection results of the floor reaction force sensor 42. Specifically, the control unit 40 identifies the phase of the walking movement of the wearer by comparing the load transition state on the soles of the feet based on the floor reaction force data with the load transition state of the reference parameters stored in the reference parameter database of the data storage unit 41.

[0041] The control unit 40 divides the identified walking phase into a swing phase and a supporting phase. The swing phase is the period when the foot leaves the ground and the lower leg swings out. The supporting phase is the period when the foot is in contact with the ground and supports the body's own weight.

[0042] When the wearer walks, the rear foot (heel) lands first, so the floor reaction force on the rear foot side increases before the floor reaction force on the forefoot side (toe side).When leaving the floor, the rear foot leaves the floor first, followed by the forefoot, so the floor reaction force on the forefoot side decreases later than the floor reaction force on the rear foot side.

[0043] Using these, the control unit 40 determines the phase based on information on the floor reaction force on the forefoot side and the floor reaction force on the rearfoot side of the shoe sole (floor reaction force data representing the load). When the floor reaction force on the rearfoot side increases, it determines that the phase has switched from the swing phase to the supporting phase, and when the floor reaction force on the forefoot side decreases, it determines that the phase has switched from the supporting phase to the swing phase.

[0044] Furthermore, the control unit 40 controls the electromagnetic solenoid of the locking mechanism unit 35 based on the calculation result of the walking synchronization, thereby fixing or releasing the rotational state of the lower leg side link unit 34 and the bending link unit 32.

[0045] In practice, the control unit 40 controls the locking mechanism 35 at the knee joint connecting unit 30 to limit the flexion of the wearer's knee joint within a predetermined range, thereby fixing the rotational state of the flexion link unit 32 in the flexion direction relative to the lower leg link unit 34 (Figure 5(A)).

[0046] The control unit 40 then controls the locking mechanism 35 to release the rotation of the bending link 32 in the bending direction relative to the crus side link 34 (Fig. 5(B)). When the locking mechanism 35 is released in the knee joint connecting unit 30, the bending link 32, patella link 33, and crus side link 34 are in a state where they can freely rotate relative to the thigh side link 31 so that the wearer's knee joint can be flexed or extended (Fig. 5(C)).

[0047] In the body weight supported walking assistance device 1, a biosignal detection unit 50 (Figure 4) is attached to the wearer's thigh on the side where the thigh frame 3 is placed, and is configured to detect biosignals resulting from the wearer's walking movement.

[0048] Furthermore, the control unit 40 causes the drive unit (rotation drive unit) 20 to generate power according to the wearer's intention when transitioning from the supporting leg phase to the swing leg phase based on the detection result of the biological signal detection unit 50. The actuator control unit 22 of the drive unit 20 controls the drive of the actuator 21 based on the detection result of the biological signal detection unit 50 sent from the control unit 40, thereby transmitting the drive torque of the actuator 21 according to the movement of the hip joint of the wearer to the hip joint as an assist force.

[0049] (3) Walking behavior of a person wearing a body weight support walking assist device In the above-described configuration, in the body weight-supported walking assistance device 1 according to this embodiment, when the wearer walks with his or her buttocks supported on the seat 2, the control unit 40 fixes the locking mechanism 35 of the knee joint connecting unit 30 in the early stage of the supporting leg phase of the walking motion (from the initial ground contact to the load response phase) (FIG. 6).

[0050] As shown in Figure 6, the locking mechanism 35 of the knee joint connecting part 30 is fixed so that the line of action F1 of the floor reaction force obtained from the sole of the wearer's foot in the shoe part is located forward of the instantaneous center P1 (the center point when a mass point moving on an arbitrary curve rotates around a certain point abruptly at a certain moment) between the thigh side link part (fixed joint) 31 and the crus side link part (intermediate joint) 34.

[0051] 7, as the wearer's walking movement progresses and the links of the four-bar link mechanism of the knee joint connecting part 30 move backward, in the middle of the supporting leg phase (from mid-stance phase to mid-stance end phase), the control part 40 releases the locking mechanism part 35 of the knee joint connecting part 30. At this time, the line of action F1 of the floor reaction force obtained from the sole of the wearer's foot of the shoe part 5 tilts slightly backward from the vertical, and at the same time, the position of the instantaneous center P1 between the thigh side link part 31 and the crus side link part 34 moves backward and upward, thereby increasing the stability of supporting the wearer's weight.

[0052] 8, as the wearer's walking movement progresses and the links of the four-bar link mechanism of the knee joint connecting part 30 move forward, the thigh side link part 31 begins to bend relative to the crus side link part 34 in the latter part of the supporting leg phase (from the end of the stance phase to the forward swing phase). At this time, the line of action F1 of the floor reaction force obtained from the sole of the wearer's shoe part moves rearward from the position of the instantaneous center P1 between the thigh side link part 31 and the crus side link part 34.

[0053] Thereafter, when the walking motion transitions from the swing phase to the supporting phase, the control unit 40 fixes the rotational state of the locking mechanism 35 in the bending direction so as to limit the bending of the wearer's knee joint to a predetermined range, and then, when the walking motion transitions from the supporting phase to the swing phase, as shown in Figures 6 to 8 above, releases the locking mechanism 35 so that the wearer's knee joint can be flexed or extended.

[0054] Furthermore, in the body weight supported walking assistance device 1, the control unit 40 generates power in the drive unit (rotation drive unit) 20 in accordance with the wearer's intentions when transitioning from the supporting leg phase to the swing leg phase based on the detection results of the biological signal detection unit 50.

[0055] In this way, the body weight supported walking assist device 1 can assist movement while reducing the load on the knee joint caused by the wearer's own weight by reducing the floor reaction force during the supporting leg phase of walking.

[0056] (4) Walking motion experiment by a wearer wearing a body weight support walking assist device The results of an experiment in which a wearer (a healthy adult male weighing 60 kg) walked five times over a distance of 10 m with and without the weight-supported walking aid device of this embodiment on his left leg, with a margin of 3 m in front and behind, will be described below.

[0057] In rehabilitation after regenerative medicine treatment, walking training is first performed by placing a load of one-third of the wearer's total body weight on the lower limb on which the device is attached, and the load is then increased according to the state of cell adhesion.The walking movement was then confirmed when the load on the lower limb on which the device is attached was one-third (Figure 9), one-half (Figure 10), and two-thirds (Figure 11) of the wearer's total body weight.

[0058] As shown in Figure 9, when the load on the left leg (with device) wearing the body weight supported walking aid device 1 is adjusted to one-third of total body weight relative to the right leg (w / o device) not wearing the device, the wearer actually performs walking movements and the detection results of the left and right floor reaction force sensors 42 (pressure distribution on the soles of the wearer's feet) are measured.As a result of five trials, it was confirmed that the load on the lower limbs wearing the body weight supported walking aid device is almost below the maximum allowable load value (one-third of total body weight).

[0059] Similarly, in Figure 10, when the load on the left leg (with device) wearing the body weight supported walking aid device 1 is adjusted to half of the total body weight relative to the right leg (w / o device) not wearing the device, the wearer actually walks and the detection results (pressure distribution on the soles of the wearer's feet) of the left and right floor reaction force sensors 42 are measured.As a result of five trials, it was confirmed that the load on the lower limbs wearing the body weight supported walking aid device is almost below the maximum allowable load value (half of the total body weight).

[0060] Similarly, in Figure 11, when the load on the left leg (with device) wearing the body weight supported walking aid device 1 is adjusted to two-thirds of total body weight relative to the right leg (w / o device) not wearing the device, the wearer actually walks and the detection results (pressure distribution on the soles of the wearer's feet) of the left and right floor reaction force sensors 42 are measured.As a result of five trials, it was confirmed that the load on the lower limb wearing the body weight supported walking aid device 1 is almost below the maximum allowable load value (two-thirds of total body weight).

[0061] According to the results of the three types of partial load trials shown in Figures 9 to 11 above, it was confirmed that in 96% of all trials, the load on the lower limbs wearing the body weight supported walking aid device 1 was below the maximum allowable load value.

[0062] (5) Other embodiments As described above, in this embodiment, the body weight assisted walking aid device 1 is described as using a knee joint connecting section with a closed loop structure consisting of a four-bar link mechanism, but the present invention is not limited to this, and it is also possible to use a body weight assisted walking aid device 61 having a knee joint connecting section 60 with a joint structure equipped with a locking mechanism as shown in FIG. 12, in which the same reference numerals are used for parts corresponding to those in FIG. 1.

[0063] As shown in Figure 13(A), the knee joint connecting portion 60 is engaged with a lower leg side part 70 connected to the end of the lower leg frame 4 and a thigh side part 71 connected to the end of the thigh frame 3 so that they can rotate and move within a predetermined range.

[0064] Figure 13(B) shows the internal structure of the knee joint connecting part 60. As shown in Figure 13(B), the convex part 71Y of the thigh side part 71 fits freely into the concave part 70X of the crus side part 70, and the pin PN formed on the convex part 71Y is engaged so as to be able to slide along the slide hole SH (Figure 13(A)) formed in the concave part 70X.

[0065] As shown in Figure 14(A), a locking protrusion 70XZ is formed at the end of the recess 70X of the crus side part 70, and the base of the convex part 71Y of the thigh side part 71 abuts against the locking protrusion 70XZ, thereby preventing and restricting movement in the abutment direction. At that time, as shown in Figure 14(B), the pin PN of the thigh side part 71 is designed to abut against the lower end of the slide hole SH of the crus side part 70.

[0066] A locking mechanism 72 is provided in the recess 70X of the crus side part 70. The locking mechanism 72 allows a substantially rectangular parallelepiped stopper ST to slide vertically (in the linear direction indicated by arrow A) in response to the operation of an electromagnetic solenoid. When the stopper ST is positioned at the bottom end as shown in Fig. 15(A), the thigh side part 71 can rotate relative to the crus side part 70 in the bending direction (the rotation direction indicated by arrow B) as shown in Fig. 15(B). When the stopper ST is positioned at the top end, the thigh side part 71 is fixed at a predetermined angle relative to the crus side part 70 (see Figs. 13(A) and (B) above).

[0067] In this body weight-supported walking assistance device 61, when the wearer walks with their buttocks supported on the seat 2, the control unit 40 (which has the same configuration as in Figure 4) positions the stopper ST of the locking mechanism unit 72 at the upper end during the early supporting leg phase of the walking motion (from the initial ground contact to the load response phase), thereby restricting the bending state of the knee joint connecting unit 60 and preventing the wearer's knee from bending.

[0068] As the wearer continues walking, in the middle of the supporting leg phase (from mid-stance to mid-stance end), the base of the convex portion 71Y of the thigh side part 71 abuts against the engaging protrusion 70XZ of the recess 70X of the crus side part 70, causing the knee joint connecting portion 60 to enter an extended state, making it possible to stably support the wearer's weight.

[0069] As the wearer's walking movement progresses, in the later stage of the supporting leg phase (from the end of the stance phase to the forward swing phase), the control unit positions the stopper ST of the locking mechanism unit 72 at the lower end, causing the thigh frame 3 to begin to bend relative to the lower leg frame 4.

[0070] Thereafter, when the walking motion transitions from the swing leg phase to the supporting leg phase, the control unit 40 positions the stopper ST of the locking mechanism unit 72 at the upper end to fix the rotational state so as to limit the flexion of the wearer's knee joint to a predetermined range, and then when the walking motion transitions from the supporting leg phase to the swing leg phase, the control unit 40 positions the stopper ST of the locking mechanism unit 72 at the lower end so that the wearer's knee joint can flex or extend.

[0071] An experiment similar to the walking motion experiment described above was also conducted with this body weight support type walking assist device 61. Figure 16 shows the relationship between the load value during one walking cycle of the wearer and the movement control of the stopper ST of the locking mechanism 72. As a result, it was confirmed that the stopper ST of the locking mechanism 72 operates (moves to the upper end) when the wearer's leg not wearing the device touches the ground, enabling walking.

[0072] Furthermore, according to the load values ​​of the left and right lower limbs in the 10 m walking test shown in Figure 17(A) and the peak load value of the lower limbs wearing the body weight support type walking assist device 61 shown in Figure 17(B), it was confirmed that the load on the lower limbs wearing the body weight support type walking assist device 61 was 196 [N], which did not exceed the maximum allowable load value. The average and standard error of the peak value for each trial was 181 ± 12.8 [N].

[0073] In addition, in this embodiment, we have described a case where an insole-type floor reaction force sensor 42 is provided on the soles of the left and right shoe parts 5 to detect the reaction force (pressure distribution on the soles) against the load applied to the soles of the wearer's feet, but the present invention is not limited to this, and in addition to the floor reaction force sensor 42, a seat reaction force sensor (not shown) may also be provided in the seat part.

[0074] That is, the seat is further equipped with a seat reaction force sensor that is mounted on the seat and detects the pressure distribution on the wearer's buttocks, and the control unit 40 controls the drive unit (rotating drive unit) 20 based on the detection results of the biological signal detection unit 50 and the seat reaction force sensor so that the shoe does not come into contact with the walking surface during the swing phase of walking.

[0075] As a result, the body weight supported walking assistance device 1 can assist movement by reducing the floor reaction force during the supporting leg phase of walking based on the pressure distribution not only on the soles of the wearer's feet but also on the pressure distribution on the wearer's buttocks, thereby optimizing the weight burden on the knee joint caused by the wearer's own weight with high precision. [Explanation of symbols]

[0076] 1, 61...body weight supported walking assist device, 2...seat, 3...thigh frame, 4...lower leg frame, 5...shoe part, 7, 8...cuff, 10...hip joint connecting part, 20...drive unit (rotational drive part), 21...actuator, 22...actuator control part, 23...reduction gear, 30, 60...knee joint connecting part, 31...thigh side link part (fixed joint), 32...flexion link part (prime link), 33...patella link part (follower link), 34...lower leg side link part (intermediate link), 35, 72...locking mechanism part, 40...control part, 41...data storage part, 42...floor reaction force sensor, 43...floor reaction force control part, 44...converter, 45...LPF, 50...biological signal detection part, 70...lower leg side part, 71...thigh side part

Claims

1. a seat that supports the wearer's buttocks; a thigh frame and a lower leg frame disposed along the inside of the wearer's leg; a hip joint connecting portion that connects the underside of the seat portion and one end of the thigh frame and is rotatable in accordance with the movement of the hip joint of the wearer; a rotation drive unit provided at the hip joint connection unit and configured to drive the thigh frame relative to the seat unit in a rotation direction of the hip joint unit; a knee joint connecting part that connects the other end of the thigh frame and one end of the lower leg frame and is rotatable in accordance with the movement of the knee joint of the wearer; a locking mechanism for fixing or releasing the rotational state of the knee joint connecting portion; Shoe parts are attached to the left and right feet of the wearer, one of which is joined to the other end of the lower leg frame; a floor reaction force sensor attached to each of the left and right shoe parts to detect a pressure distribution on the soles of the wearer's feet; a biological signal detection unit attached to the wearer's thigh on the thigh frame arrangement side and detecting a biological signal resulting from the wearer's walking motion; a gait synchronization calculation unit that calculates the gait cycle of the wearer based on the detection result of the floor reaction force sensor; a control unit that, based on a calculation result of the walking synchronization calculation unit, fixes a rotational state of the locking mechanism unit in the bending direction so as to limit the bending of the knee joint of the wearer to a predetermined range when transitioning from a swing phase to a supporting phase of a walking motion, and releases the locking mechanism unit so as to allow the knee joint of the wearer to bend or extend when transitioning from the supporting phase to the swing phase; and the control unit generates power in the rotation drive unit according to the wearer's intention when transitioning from the supporting leg phase to the swing leg phase based on the detection result of the biological signal detection unit. A weight-support type walking assistance device characterized by:

2. The control unit adjusts the fixed range of the rotational state of the locking mechanism unit so that the load amount on the knee joint of the wearer increases in accordance with a transition state of the knee joint of the wearer in a correction direction toward improving symptoms of the knee joint of the wearer.

2. The body weight support type walking assistance device according to claim 1.

3. Further, a seat reaction force sensor is mounted on the seat and detects a pressure distribution on the buttocks of the wearer. The control unit controls the rotation drive unit based on the detection result of the biological signal detection unit and the detection result of the seat reaction force sensor so that the shoe unit does not come into contact with the walking surface during the swing phase of a walking motion.

3. The body weight support type walking assistance device according to claim 1 or 2.

4. While the wearer's buttocks are supported by the seat, a thigh frame and a lower leg frame are arranged along the inside of the wearer's legs, and shoe parts, one of which is joined to the other end of the lower leg frame, are worn on the wearer's left and right feet.Furthermore, a hip joint connecting part connecting the underside of the seat to one end of the thigh frame is made rotatable in response to movement of the wearer's hip joint, and a knee joint connecting part connecting the other end of the thigh frame to one end of the lower leg frame is made rotatable in response to movement of the wearer's knee joint, a rotation drive unit is provided at the hip joint joint, which drives the thigh frame in a rotation direction of the hip joint joint relative to the seat, and a lock mechanism is provided to fix or release the rotation state of the knee joint joint, a first step of detecting a pressure distribution on each sole of the wearer's foot in the left and right shoe parts; a second step of calculating a walking cycle of the wearer based on the detection result of the first step; a third step of fixing a rotational state of the locking mechanism in a bending direction so as to limit bending of the wearer's knee joint within a predetermined range when transitioning from a swing phase to a supporting phase of a walking motion based on a calculation result of the second step, and releasing the locking mechanism so as to allow bending or extension of the wearer's knee joint when transitioning from the supporting phase to the swing phase; a fourth step of detecting a biological signal resulting from the wearer's walking motion at the thigh of the wearer on the thigh frame arrangement side; a fifth step of generating power in the rotation drive unit according to the wearer's intention at the transition from the supporting leg phase to the swing leg phase in the third step based on the detection result of the fourth step; A control method for a body weight supported walking assistance device, comprising:

5. In the third step, the fixing range of the rotational state of the locking mechanism is adjusted so that the load amount on the knee joint of the wearer increases in accordance with the transition state of the correction direction toward improving the symptoms of the knee joint of the wearer.

5. A method for controlling a body weight support walking assistance device according to claim 4.

6. a sixth step of detecting a pressure distribution on the buttocks of the wearer in the seat portion, In the fifth step, the rotation drive unit is controlled based on the detection results of the fourth step and the sixth step so that the shoe part does not come into contact with the walking surface during the swing phase of the walking motion.

6. A method for controlling a body weight support type walking assistance device according to claim 4 or 5.

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