JP3624693B2 - Lower limb drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lower limb driving device for driving a lower limb among limb body driving devices such as a rehabilitation support device and a training device used for restoring the function of the limb.
[0002]
[Prior art]
Conventional rehabilitation support devices and training devices used to recover limb functions that have weakened muscles mechanically drive the limbs from the outside centered on the joints, or put a load on the movement of the joints There are devices and various mechanisms have been proposed.
One of such conventional limb drive devices is a device having a plurality of degrees of freedom of drive, and is disclosed in “Continuous Passive Exercise Device” of Japanese Patent Application Laid-Open No. 7-323048. This device performs impedance control with the limbs attached to a multi-degree-of-freedom mechanism when teaching movement, and teaches impedance control with the rotation angle stored in memory as the equilibrium point when treating. It is characterized by having a means to reproduce the exercise and force. As another limb body drive device, a rotary motion mechanism that applies a force to the thigh and induces motion, and a limb body support that supports the lower leg and can freely control the position and posture of the lower leg in a plane. There is one provided with a motion mechanism of a degree of freedom, which is disclosed in “Continuous Passive Motion Device for Knee Joint” of JP-A-8-196585. As another limb body drive device, there is one which is arranged so that the shape formed by the drive shaft of the device and the joint of the limb body is a quadrilateral, which is disclosed in “joint drive device” of Japanese Patent Laid-Open No. 9-99021. Yes.
[0003]
Of these, the first conventional example will be described with reference to FIG. In the figure, 410 is a first arm that applies a force to the thigh to rotate the thigh around the hip joint, and 420 is a second arm that applies a force to the lower thigh to rotate the thigh around the knee joint. The lower limb drive device 400 is installed as a whole. The first arm 410 includes a drive shaft 411, a link member 415, a free joint 413, a roller 412, and a force detector 414. The second arm 420 includes a drive shaft 421, 422, link members 425, 426, A free joint 423 and a force detector 424 are included. The drive shaft 411 is provided on the base, and the link member 415 can be rotated by a motor built in the base. A free joint 413 is provided at the tip of the link member 415, and a member provided with two rollers 412 is rotatable around the free joint 413. The two rollers 412 are rotatable. When the rollers 412 are pressed against the thigh and move relative to each other, the rollers 412 roll on the thigh surface and rotate. A force detector 414 is attached to the link member 415 so that the force applied to the thigh by the first arm 410 can be detected. The drive shaft 421 is provided on the base, and the link member 425 can be rotated by a motor built in the base. Another drive shaft 422 is provided at the tip of the link member 425, and the link member 426 is independent of the movement of the link member 425 via a mechanism in the link member 425 by a motor built in the base. Can be rotated. A free joint 423 is provided at the distal end of the link member 426, and rotatably supports a member to which the lower limb is attached. A force detector 424 is attached to the link member 426 so that the force applied to the lower leg by the second arm 420 can be detected. The drive shafts 411, 421, and 422 that are rotatable, the free joints 413 and 423, and the roller 412 can rotate about axes that are perpendicular to the paper surface.
[0004]
When the lower limb driving apparatus 400 is used, first, the patient's thigh lying on the roller 412 of the first arm 410 is applied, and the lower leg is fixed to the distal end of the second arm 420. When the patient's lower limb is driven, the first arm 410 rotates the drive shaft 411 to press the roller against the thigh, and rotates the thigh around the hip joint. At that time, although the thigh and the roller 412 are in contact with each other, they move relative to each other, so that the roller 412 rotates. Even if the center of rotation of the first arm 410 and the center of rotational movement of the thigh are deviated, the roller 412 comes into contact with the thigh and rolls, and the two rollers 412 rotate around the free joint 413, so that there is a clearance at the contact portion. The thigh can be driven without occurrence. The second arm 420 can drive the lower limbs by two-degree-of-freedom movement of the drive shafts 421 and 422, and can rotate the lower leg around the knee joint regardless of the movement of the first arm 410. Since each of the first arm 410 and the second arm 420 includes a force sensor, it can be driven with an appropriate load on the lower limbs by controlling the force with a control device (not shown).
[0005]
Next, a second conventional example will be described with reference to FIG. In the figure, reference numeral 501 is a base, 502 is a drive shaft, 503 and 505 are link members, 504 and 506 are rotation mechanism portions, and 507 is a mounting portion. The drive shaft 502 is attached to the base 501 and the link member 503 can be rotated by a built-in motor. The link members 503 and 505 are rotatably connected by a rotation mechanism portion 504, and the link member 505 and the mounting portion 507 are rotatably connected by a rotation mechanism portion 506.
When using this lower limb drive device 500, the thigh of a lying patient is fixed to the mounting portion 507. At that time, the mounting portion 507 is mounted so that the hip joint 508, the driving shaft 502, and the rotation centers of the rotation mechanism portions 504 and 506 are parallel quadrilaterals.
When the limb drive device 500 configured as described above is used, when the drive shaft 502 is rotated by the built-in motor, the rotational force is applied to the lower limbs via the link members 503 and 505, and the thighs 508 are the center. Rotates. Since the link member 505 and the base 501 and the link member 503 and the thigh are moved in parallel, the hip joint 508 can be driven by the movements shown in FIGS. 3 (a) and 3 (b).
[0006]
[Problems to be solved by the invention]
However, in the case of the lower limb drive device 400 of the first conventional example, it is difficult to apply force as the angle at which the hip joint is bent increases as the drive shaft 411 and the hip joint are separated from each other by an appropriate distance. There was a problem of becoming. On the other hand, when the configuration of the second conventional example is used, the center of rotation can be adjusted even if the positional relationship between the drive shaft 502 and the hip joint 508 is slightly shifted. A force can be applied to the thigh. Therefore, when combining the two conventional examples to make up for the shortcomings, the positional relationship with the second arm 420 that moves the lower leg, the position on the patient's device, the individual difference in the patient's lower limb length, the individual difference in the lower limb shape It is undeniable that due to various factors such as hip joint internal and external rotation and internal / external rotation restrictions, the legs will not move smoothly and the legs will not move smoothly, or an excessive load will be applied to the legs. There was a problem not to be.
The present invention has been made to solve the problems of the conventional techniques, and an object of the present invention is to provide a lower limb drive device that can move the lower limbs smoothly without imposing an excessive load on the lower limbs. It is what.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a thigh motion mechanism portion that is controlled by a control device and applies a force to the thigh to rotate the hip joint and a thigh motion mechanism that applies a force to the lower thigh to rotate the knee joint. In the lower limb drive device, the thigh motion mechanism is installed on a base, and is connected to a first drive shaft driven by a motor built in the base, and the first drive shaft by a link member An interlocking drive shaft that mechanically reverses by the same angle according to the rotation of the first drive shaft, a rotatable free joint connected to the interlocking drive shaft by a link member, and the free joint And a thigh mounting portion that fixes the thigh by being fixed to the slide mechanism, and the crus motion mechanism portion is installed on a base and is driven by a motor built in the base. The axis, A third drive shaft connected to the second drive shaft by a link member and driven independently from the second drive shaft by a motor built in the base, and the third drive shaft and the link member It is characterized by comprising a connected free rotatable joint, a free rotating part connected to the free joint, and a lower leg mounting part fixed to the free rotating part and fixing the lower leg. The subordinate invention of the present invention is provided with at least one of a force detector for the thigh motion mechanism section for detecting a force applied to the thigh and a force detector for the thigh motion mechanism section for detecting a force applied to the thigh. , The information is fed back to the control device, and at least one of the thigh motion mechanism unit for detecting the angle of the free joint and the angle sensor for the crus motion mechanism unit is provided, and the information is Feedback is provided to the control device, and further, a touch sensor is provided on a link member of the thigh motion mechanism and the crus motion mechanism, and the signal is fed back to the control device. According to a fifth aspect of the present invention, in the lower limb drive device comprising an crus motion mechanism unit that is controlled in operation by a control device and applies a force to the crus to rotate the knee joint, the crus exercise mechanism unit is a base And a first drive shaft that is driven by a motor built in the base, and is connected to the first drive shaft by a link member, and is independent of the first drive shaft by a motor built in the base. The second drive shaft driven in this manner, a rotatable free joint connected to the second drive shaft by a link member, a free rotating portion connected to the free joint, and a fixed to the free rotating portion A lower leg mounting part for fixing the lower leg , wherein the free rotation part freely rotates about an axis perpendicular to the longitudinal axis of the lower leg and perpendicular to the rotation axis of the free joint. cage, its dependent invention, Comprising a Tchisensa, a force detector for detecting a force applied to the lower leg, the angle detector detects the angle of the free joints, or the said angle detector and said force detector, their detection values the control device It is characterized by being fed back. By such means, it is possible to absorb a positional shift generated in the wearing portion and an unreasonable load applied to the lower limbs, so that the lower limbs can be driven smoothly.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a lower limb driving apparatus 100 showing an embodiment of the present invention. In the figure, 110 is a thigh exercise mechanism unit, and 120 is a thigh exercise mechanism unit, both of which are installed on the same base and drive the thigh and the lower thigh, respectively.
The thigh motion mechanism unit 110 includes a thigh mounting unit 115 that is mounted on the thigh of a patient 116, a first drive shaft 111 that is provided on the base and is driven by a motor built in the base, an interlocking drive shaft 112, a free The joint 113 is composed of a linear motion free joint, that is, a slide mechanism 114. When the thigh motion mechanism unit 110 is used, the first drive shaft 111, the interlocking drive shaft 112, and the free joint 113 are arranged so as to form a substantially parallelogram with respect to the hip joint 117. The interlocking drive shaft 112 is driven by the motor of the first drive shaft 111, and torque is transmitted via a mechanism in the link member between the first drive shaft and the interlocking drive shaft 112, and is interlocked with the first drive shaft. And it moves in the opposite direction by the same angle. In addition, the slide mechanism provided between the thigh mounting portion 115 and the free joint 113 can absorb a deviation from an appropriate distance between the patient 116 and the lower limb driving device 100 and a positional deviation caused by individual differences in the lower limb length of the patient. It can be done. Because of such a configuration, a target load is applied to the thigh regardless of the rotational angle of the hip joint 117 or the first drive shaft 111 and a slight positional deviation remains. Can do.
[0009]
The crus exercise mechanism 120 includes a crus attachment part 125 to be attached to the crus of the patient 116, a second drive shaft 121, a third drive shaft 122, which are provided on the base and driven by a motor built in the base. A free joint 123 and a free rotating part 124 are included. The third drive shaft 122 is driven by a motor built in the base, torque is transmitted by a mechanism built in between the second drive shaft 121 and the third drive shaft 122, and the movement of the second drive shaft 121 is It can be rotated independently. The free rotating part 124 is a rotating mechanism provided between the free joint 123 and the crus mounting part 125, and is perpendicular to both the longitudinal axis of the crus fixed on the crus mounting part 125 and the rotational axis of the free joint 123. It can be freely rotated around any axis. Since the crus movement drive unit 120 has two independent drive shafts, the second drive shaft 121 and the third drive shaft 122, the crus motion drive unit 120 is loaded on the crus at an arbitrary position within the movable range within a plane parallel to the paper surface. It is possible to apply.
[0010]
When using this lower limb drive device 100, first, the patient's thigh lying on the base is placed on the first drive shaft 111, the interlock drive shaft 112, the free joint 113, and the patient's hip joint 117 in a parallelogram shape. It fixes to the thigh mounting part 115 so that it may become. Next, an appropriate position of the lower leg, approximately the middle of the lower leg, is fixed to the lower leg mounting portion 125. Then, a torque is applied to the first drive shaft 111, the second drive shaft 121, and the third drive shaft 122 by a control device (not shown), and the thigh and the lower leg are moved to give the hip joint 117 and the knee joint 118 a rotational motion. When the operation is performed, if the distance between the first drive shaft 111 and the patient's hip joint 117 is not the same as the distance between the interlocking drive shaft 112 and the free joint 113, the first drive shaft 111 or the hip joint When 117 rotates, the slide mechanism 114 slides, and the position of the free joint 113 moves with respect to the thigh. For this reason, an excessive force is not applied to the patient's thigh, and the force of the first drive shaft 111 is reliably transmitted from the thigh mounting portion 115 to the thigh. When the patient's lower limb is an O-leg, the rotation axis of the knee joint 118 is offset from the axis perpendicular to the paper surface, and the longitudinal axis of the lower leg from the knee joint 118 to the foot is parallel to the paper surface. It is not. In that case, as the knee joint 118 rotates, the shift in the degree of parallelism between the longitudinal axis of the lower leg and the paper surface changes. However, the free rotating unit 124 rotates and absorbs the movement, so that the patient The knee joint 118 can be rotated without placing a burden on the lower limb. Further, even if the degree of the O-leg is different for each patient, the difference can be absorbed by the free rotating part 124 and the lower leg can be fixed to the lower leg mounting part 125, which places a burden on the patient. Thus, the above operation can be performed.
[0011]
In the above description, only the mechanism has been described. However, when the control device that drives the lower limb drive device 100 is to perform flexible and advanced control, it can be realized by feeding back information on the lower limbs. Therefore, as shown in FIG. 2, a force detector and an angle detector are provided in the thigh motion mechanism 110 and the crus motion mechanism 120. The force applied to the thigh can be detected by a force detector provided between the free joint 113 and the slide mechanism 114, and the force applied to the lower leg is a force provided between the free joint 123 and the free rotating unit 124. It can be detected by a detector. Further, the movement position of the thigh can be detected by the angle detector 231 that detects the rotation position information of the first drive shaft 111 and the rotation angle of the free joint 113, and the movement position of the lower leg is the second and third drive shafts 121, The rotation position information 122 and the rotation angle of the free joint 123 can be detected by an angle detector 233.
[0012]
FIG. 2 is a diagram showing an example of a control device of the lower limb drive device 100 provided with such sensors, and is a control block diagram using impedance control as force control. In the figure, 210 is a control device for the thigh motion mechanism 110, and 220 is a control device for the thigh motion mechanism.
The control device 210 of the thigh motion mechanism unit 110 receives the raw signals of the force detector 230 and the angle detector 231 and amplifies or processes them to convert them into signals corresponding to the force or angle. And an impedance control unit 212 and a servo amplifier 213. The control of the control device 210 can be impedance control using the following equation because the thigh motion mechanism unit 110 has a mechanism of one degree of freedom.
Fe = Mαe + BVe + K (θ−θ0) (1)
Where Fe is the force acting between the thigh and the first arm, M, B, and K are target impedances, θ is the angle of the first arm drive shaft, θ0 is the equilibrium point of the spring stiffness of the first arm, Ve Is the angular velocity (differential value of angle θ) of the first arm drive shaft, and αe is the angular acceleration (double differential value of angle θ) of the first arm drive shaft. Since control using this equation is a known technique, detailed description thereof is omitted.
In this control system, when signals detected by the force detector 230 and the angle detector 231 are amplified by the detector converter 211 and sent to the impedance control unit 212, the impedance control unit 212 satisfies the expression (1). Thus, a motion command is generated and the motor of the first drive shaft 111 is driven via the servo amplifier 213.
[0013]
A control device 220 for the lower leg movement mechanism unit receives a raw signal from the force detector 232 and the angle detector 233, amplifies or processes the signal, and converts it into a signal corresponding to the force or angle, and a detector converter 221 , An impedance control unit 222, and a servo amplifier 223. The control of the control device 220 can be impedance control using the following equation because the crus motion mechanism 120 has two degrees of freedom.
Fx = Mαx + BVx + K (x-x0) (2)
Where Fx is the force acting between the lower leg and the second arm, M, B, and K are target impedances, x is the position of the second arm free joint (x, y), and x0 is the balance of the spring stiffness of x Point, Vx is the differential value of x , and α x is the differential value of x twice. Since control using this equation is a known technique, detailed description thereof is omitted. In this control system, when the force signal and angle signal detected by the force detector 232 and the angle detector 233 are amplified by the detector converter 221 and sent to the impedance controller 222, the impedance controller 222 (2) A motion command is generated so as to satisfy the equation, and the motors of the second drive shaft 121 and the third drive shaft 122 are driven via the servo amplifiers 223 and 224. In the above description, the case where the force detector and the angle detector are provided in both the thigh motion mechanism unit 110 and the crus motion mechanism unit 120 has been described. However, when the control method can be simplified, the detector is appropriately used. It may be omitted and reduced.
[0014]
In the above-described embodiments, the lower limb driving device 100 has been described as including the thigh motion mechanism unit 110 and the crus motion mechanism unit 120. However, even if only the crus motion mechanism unit 120 is used alone, the patient Exercise can be given to the lower limbs. The patient may need to exercise the entire lower limb, but may need to exercise only the lower leg, and there are individual differences among patients. In the case of a patient who needs to give exercise only to the lower leg, the same operation as that of the lower leg exercise mechanism unit 120 of the above embodiment is performed using only the lower leg exercise mechanism unit 120 of the present invention. Therefore, the effect is also as described above.
[0015]
Next, modifications of the present invention will be described. When using the lower limb drive device 100 of the present invention, there is a possibility that a patient's body such as a hand may be injured by being pinched by an operating link member. In this modified example, as a preventive measure, a contact sensor is provided on the link member so that an emergency stop can be made by detecting the contact. A case where a contact sensor, that is, a touch sensor is attached will be described with reference to FIG. The figure shows a simple example of (a) a touch sensor mounting state and (b) an emergency stop circuit for outputting a contact as a signal. As shown in (a), the touch sensor mounting portion includes upper and lower surfaces of the link member between the drive shaft 111 and the interlocking drive shaft 112, and upper and lower surfaces of the link member between the drive shaft 121 and the drive shaft 122. These are five locations on the upper surface of the link member between the drive shaft 122 and the free joint 123. As described above, since the limbs of the link member are sandwiched and arranged at a cheap place, it is possible to easily know when a hand or the like is sandwiched. Pressurized conductive rubber is used for the touch sensor used here, and A and B code-type electrodes are provided in parallel inside, and a member such as elastic rubber is sandwiched between them. It is. When a certain level of pressure is applied to a part of the circuit, a short circuit occurs. FIG. 3B is an example of an emergency stop circuit for a touch sensor. One end of the touch sensor is pulled up to HI level (24V), and the other end is dropped to GND (0V) via a relay control terminal. Keep it. If the relay is connected in series with the servo-on circuit, when the touch sensor is pressed, A and B are short-circuited, the relay terminal is opened, the servo is cut, and the motor is stopped. Cutting at the relay terminals is not limited to this, and may be a main power supply or a speed command signal. Moreover, although the example which provided the touch sensor in five places of three link members was demonstrated, as long as the place which installs a touch sensor seems to be dangerous, it may be provided anywhere and is not restricted to three link members. You may provide in all four link members.
[0016]
【The invention's effect】
As described above, according to the present invention, it is possible to absorb the deviation from the appropriate value of the distance between the lower limb driving device and the patient lying on the side and the rotation of the lower leg shaft due to the degree of the O leg, thereby placing a burden on the patient. Since the lower limbs can be driven without any problem, it is possible to provide a leg drive device that is easy on the patient and highly practical.
[Brief description of the drawings]
FIG. 1 is a side view showing a lower limb drive device of the present invention. FIG. 2 is a block diagram including a lower limb drive device and a control device. FIG. 3 is a view showing a modification of the present invention. Side view showing the driving device FIG. 5 is a side view showing the lower limb driving device of the second conventional example.
100, 200, 300, 400, 500 Lower limb drive unit 110 Thigh motion mechanism 111, 121, 122, 411, 421, 422, 502 Drive shaft 112 Interlocked drive shaft 113, 123, 413, 423 Free joint 114 Slide mechanism 115 Thigh mounting part 116 Patient 117, 508 Hip joint 118 Knee joint 120 Lower leg movement mechanism part 124 Free rotation part 125 Lower leg mounting part 210, 220 Controller 211, 221 Detector converter 212, 222 Impedance control part 213, 223, 224 Servo Amplifier 230, 232, 424 Force detector 231, 233 Angle detector 301, 302, 303, 304, 305 Touch sensor 410 First arm 412 Roller 420 Second arm 501 Base 415, 425, 426, 503, 505 Link member 5 04, 506 Rotation mechanism 507 mounting part

Claims (6)

In the lower limb drive device, the operation of which is controlled by the control device and which includes a thigh motion mechanism unit that applies a force to the thigh to rotate the hip joint and a crus motion mechanism unit that applies a force to the lower thigh to rotate the knee joint, The motion mechanism unit is installed on a base, and is connected to a first drive shaft driven by a motor built in the base, the first drive shaft and a link member, and according to the rotation of the first drive shaft. An interlocking drive shaft that mechanically reversely rotates by the same angle, a rotatable free joint connected to the interlocking drive shaft by a link member, a slide mechanism connected to the free joint, and a fixed to the slide mechanism A thigh mounting part for fixing the thigh,
The crus motion mechanism is installed on a base and is driven by a motor built in the base, and is connected to the second drive shaft by a link member, and is a motor built in the base. A third drive shaft that is driven independently of the second drive shaft; a rotatable free joint connected to the third drive shaft by a link member;
A free rotating part connected to the free joint;
A lower limb drive device comprising: a lower leg mounting portion fixed to the free rotating portion and fixing the lower leg. There is provided at least one of a force detector of the thigh motion mechanism unit for detecting a force applied to the thigh and a force detector of the thigh motion mechanism unit for detecting a force applied to the thigh, the information of which is The lower limb drive device according to claim 1, wherein the lower limb drive device is fed back to the control device. At least one of the thigh motion mechanism unit for detecting the angle of a free joint and the angle detector for the crus motion mechanism unit is provided, and the information is fed back to the control device. Item 1. A lower limb drive device according to item 1. The lower limb drive device according to claim 1, wherein a touch sensor is provided on a link member between the thigh motion mechanism unit and the crus motion mechanism unit, and a signal thereof is fed back to the control device. In a lower limb drive device that includes an exercise mechanism for the lower leg that is controlled by the control device and rotates the knee joint by applying force to the lower leg,
The crus motion mechanism is installed on a base and is driven by a motor built in the base, and is connected to the first drive shaft by a link member, and is a motor built in the base. A second drive shaft that is driven independently of the first drive shaft; a rotatable free joint connected to the second drive shaft by a link member;
A free rotating part connected to the free joint; and a crus mounting part fixed to the free rotating part to fix the crus , wherein the free rotating part is perpendicular to the longitudinal axis of the crus and is free A lower limb drive device characterized by freely rotating about an axis perpendicular to the rotation axis of the joint . The lower leg motion mechanism is
A touch sensor;
A force detector for detecting a force applied to the lower leg,
Angle detector for detecting an angle of the free joint,
Or comprising the force detector and the angle detector,
6. The lower limb drive device according to claim 5, wherein the detected values are fed back to the control device.

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