JPH11347081A - Inferior limb driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inferior limb driving device which can move an inferior limb smoothly without loading hard load on the inferior limb. SOLUTION: This inferior limb driving device is equipped with a thigh motion mechanism part 110 to apply force to a thigh to rotate the hip joint and a lower leg motion mechanism part 120 to apply force to a lower leg to rotate the knee joint. The thigh motion mechanism part 110 comprises a drive shaft 111 driven by a motor, a motion drive shaft 112 to rotate in the direction reverse of the drive shaft 111, a rotatable free joint 113, a slide mechanism 114, and a thigh mounting part 115. The lower limb motion mechanism part 120 comprises a drive shaft 121 driven by a motor, a drive shaft 122 driven independent of the drive shaft 121, a rotatable free joint 23, a free rotation part 124, and a lower limb mounting part 125.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower limb driving device for driving a lower limb among limb driving devices such as a rehabilitation support device and a training device used for restoring the function of a limb.

[0002]

2. Description of the Related Art Conventional rehabilitation support devices and training devices used for restoring the function of a limb with reduced muscular strength include mechanically driving the limb from the outside centered on the joint and controlling the movement of the joint. There are devices for applying loads, and various mechanisms have been proposed. As one of such conventional limb driving devices, there is a device having a plurality of driving degrees of freedom, which is disclosed in "Continuous Passive Exercise Device" of JP-A-7-332048. This device is
When teaching movement, impedance control is performed with the limb attached to the multi-degree-of-freedom mechanism, and during treatment, impedance control is performed with the rotation angle stored in memory as the balance point, and the taught movement and force Is provided. Further, as another limb driving device, there are a rotary motion mechanism for applying a force to the thigh to induce a motion, and a multi-limb supporting the lower leg and freely controlling the position and posture of the lower leg in a plane. There is an apparatus having a motion mechanism with a degree of freedom, which is disclosed in "Continuous passive exercise apparatus for knee joint" in Japanese Patent Application Laid-Open No. 8-196585. As still another limb driving device, there is a limb driving device which is arranged so that the drive shaft of the device and the joint of the limb form a quadrilateral.
No. 021, "joint drive device".

[0003] First, a first conventional example will be described with reference to FIG. In the figure, reference numeral 410 denotes a first arm that applies force to the thigh to rotate the thigh around the hip joint, and 420 denotes a second arm that applies force to the lower leg to rotate the lower leg around the knee joint. It is installed to form the lower limb driving device 400 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, and the second arm 420 includes drive shafts 421 and 42.
2, link members 425, 426, free joint 4
23, and a force detector 424. Drive shaft 41
Reference numeral 1 is provided on a 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 including two rollers 412 is rotatable about the free joint 413. The two rollers 412 are rotatable, and when pressed against the thigh and relatively moved, the rollers 412 roll on the surface of the thigh,
Rotate. A force detector 414 is attached to the link member 415 so that the force applied by the first arm 410 to the thigh 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 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 tip 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.
The force applied to the lower leg by the arm 420 can be detected. The drive shafts 411 and 4 that are rotatable
21, 422, the free joints 413, 423, and the rollers 412 can rotate around axes perpendicular to the plane of the paper, respectively.

When the lower limb driving device 400 is used, first, the thigh of a patient lying on the roller 412 of the first arm 410 is applied, and the lower leg is fixed to the tip of the second arm 420. Then, when driving the lower leg of the patient, the first arm 410 rotates the drive shaft 411 to press the roller against the thigh, thereby rotating the thigh about the hip joint. At this time, the thigh and the roller 412 are in contact with each other, but relatively move, so that the roller 412 rotates. Even if the center of rotation of the first arm 410 and the center of rotation of the thigh are deviated, the roller 412 contacts the thigh and rolls, and the two rollers 412 rotate about the free joint 413. The thigh can be driven without occurrence. The second arm 420 drives the lower limb by the coordinated operation of the drive shafts 421 and 422 with two degrees of freedom, and can rotate the lower leg around the knee joint regardless of the operation of the first arm 410. Since both the first arm 410 and the second arm 420 include a force sensor, the lower limb can be driven by applying an appropriate load by controlling the force by a control device (not shown).

Next, a second conventional example will be described with reference to FIG. In the figure, reference numeral 501 denotes a base, 502 denotes a drive shaft, 503 and 505 denote link members, 504 and 506 denote rotation mechanism units, and 507 denotes a mounting unit. The drive shaft 502 is the base 50
1, and the link member 503 can be rotated by a built-in motor. Link member 50
3 and 505 are rotatably connected by a rotation mechanism 504, and the link member 505 and the mounting section 507 are connected to the rotation mechanism 5.
06 are connected rotatably. When using the lower limb driving device 500, the thigh of the patient lying down is fixed to the mounting portion 507. At this time, the mounting part 507 is mounted so that the hip joint 508, the drive shaft 502, and the rotation mechanism parts 504 and 506 become a parallelogram with the respective rotation centers as vertices. When the limb driving device 500 configured as described above is used, when the driving shaft 502 is rotated by the built-in motor, the rotational force is applied to the lower limb via the link members 503 and 505, and the thigh is centered on the hip joint 508. Rotates. Since the link member 505 and the base 501 move while the link member 503 and the thigh move in parallel, the hip joint 508 can be driven by the movement as shown in FIGS.

[0006]

However, in the case of the lower limb driving device 400 of the first conventional example, if the distance between the drive shaft 411 and the hip joint is larger than an appropriate distance, the angle at which the hip joint is bent becomes large. Accordingly, there is a problem that it becomes difficult to apply a force. 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. It is possible to apply a force to the thigh. Then, when considering combining two conventional examples to compensate for the defect, the positional relationship with the second arm 420 that moves the lower leg, the position on the patient's device,
Due to various factors such as individual differences in the length of the lower limbs of the patient, individual differences in the shape of the lower limbs, and limitations on the inversion and rotation of the hip joint, the legs may not move smoothly due to misalignment in the mounting part, or excessive load on the legs There is a problem that it cannot be denied that the device is not always excellent. The present invention has been made in order to solve the problems of the conventional technology, and has an object to provide a lower limb driving device that can smoothly move the lower limb without imposing an excessive load on the lower limb. It is assumed that.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a thigh motion mechanism for controlling the operation of a thigh and applying a force to the thigh to rotate the hip joint, and applying a force to the lower leg. A lower limb driving device comprising a lower leg exercise mechanism for rotating a knee joint, wherein the thigh exercise mechanism is mounted on a base, and a first drive shaft driven by a motor incorporated in the base, An interlocking drive shaft connected to the first drive shaft by a link member and mechanically reversely rotated by the same angle in accordance with the rotation of the first drive shaft; and a rotatable free joint connected to the interlocking drive shaft by a link member. And a slide mechanism connected to the free joint, and a thigh mounting section fixed to the slide mechanism to fix the thigh, wherein the lower leg exercise mechanism section is installed on the base and built into the base. motor A second drive shaft to be driven, a third drive shaft connected to the second drive shaft by a link member, and driven independently of the second drive shaft by a motor built in the base. A rotatable free joint connected to the third drive shaft by a link member, a free rotating portion connected to the free joint, and a lower leg mounting portion fixed to the free rotating portion to fix a lower leg; It is characterized by consisting of. A dependent invention of the invention is provided with at least one of a force detector of the movement mechanism for the thigh detecting a force applied to the thigh, and a force detector of the movement mechanism for the lower thigh detecting a force applied to the lower leg. The information is fed back to the control device, and at least one of the thigh motion mechanism unit and the lower leg motion mechanism unit for detecting the angle of the free joint is provided, and the information is provided. A feedback is provided to the control device, and a touch sensor is provided on a link member of the thigh exercise mechanism and the lower leg exercise mechanism, and a signal thereof is fed back to the control device.
According to a fifth aspect of the present invention, there is provided a lower limb driving device which is controlled by a control device and includes a lower leg exercise mechanism for rotating a knee joint by applying a force to the lower leg, wherein the lower leg exercise mechanism is a base. And a first drive shaft driven by a motor built in the base, connected to the first drive shaft by a link member, and independent of the first drive shaft by a motor built in the base. A second drive shaft that is driven as a unit, a rotatable free joint connected to the second drive shaft by a link member, a free rotation unit connected to the free joint, and fixed to the free rotation unit And a lower leg mounting portion for fixing the lower leg, wherein the dependent invention is directed to a force detector for detecting a force applied to the lower leg, an angle detector for detecting an angle of a free joint, and a touch sensor. At least One has been characterized in that it is fed back to the control device provided on the lower leg for motion mechanism. With such a means, since a positional shift generated in the mounting portion and an unreasonable load on the lower limb can be absorbed, the lower limb can be driven smoothly.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a lower limb driving device 100 showing an embodiment of the present invention. In the figure, 110
Is a thigh exercise mechanism, and 120 is a lower leg exercise mechanism, both of which are mounted on the same base and drive the thigh and the lower thigh, respectively. The thigh motion mechanism section 110 is used for the patient 116.
A thigh mounting portion 115 mounted on the thigh, a first drive shaft 111 provided on the base and driven by a motor built in the base, an interlocking drive shaft 112, a free joint 113,
It is composed of a linearly moving free joint, that is, a slide mechanism 114. When the thigh motion mechanism section 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 a motor of the first drive shaft 111, and torque is transmitted via a mechanism in a link member between the first drive shaft and the interlocking drive shaft 112, and is interlocked with the first drive shaft. Then they move in the opposite direction by the same angle. Also, the thigh mounting part 11
The slide mechanism provided between the joint 5 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 shift caused by individual differences in the length of the lower limbs of the patient. ing. With such a configuration, the hip 117 or the first drive shaft 1
The target load can be applied to the thigh irrespective of the rotation angle of 11 and despite the fact that some displacement remains.

The lower leg motion mechanism 120 includes a lower leg mounting portion 125 mounted on the lower leg of the patient 116, and a second drive shaft 1 provided on the base and driven by a motor built in the base.
21, a third drive shaft 122, a free joint 123, and a free rotating section 124. Third drive shaft 12
2 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 rotates independently of the movement of the second drive shaft 121. Can be driven. Free rotating section 12
Reference numeral 4 denotes a rotation mechanism provided between the free joint 123 and the lower leg mounting portion 125, and a longitudinal axis of the lower leg fixed on the lower leg mounting portion 125 and the free joint 123.
Can be freely rotated around an axis perpendicular to both rotation axes. Since the lower leg motion drive unit 120 has two independent drive shafts, the second drive shaft 121 and the third drive shaft 122, the lower leg motion drive unit 120 applies a load to the lower leg at an arbitrary position within the movable range within a plane parallel to the paper surface. Is possible.

When using the lower limb driving device 100,
First, the patient's thigh lying on the base is placed on the first drive shaft 1.
11, an interlocking drive shaft 112, a free joint 113,
The patient's hip joint 117 is fixed to the thigh mounting portion 115 such that the patient has a substantially parallelogram. Next, an appropriate position of the lower leg, approximately near the center 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) to rotate the thigh and the lower leg, so that the hip joint 117 and the knee joint 118 are rotated. When performing the operation, 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 the 117 rotates, the slide mechanism 114 slides,
The position of the free joint 113 moves with respect to the thigh. For this reason, no excessive force is 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 lower leg of the patient has an O-leg, the rotation axis of the knee joint 118 is shifted from the axis perpendicular to the plane of the paper, and the longitudinal axis of the lower leg from the knee joint 118 to the foot is parallel to the plane of the paper. Not. In this case, with the rotation of the knee joint 118, the deviation of the degree of parallelism between the longitudinal axis of the lower leg and the paper surface changes, but the free rotation shaft 124 rotates to absorb the movement, and The knee joint 118 can be rotated without burdening the lower limbs. In addition, even if the degree of the O-leg may differ from patient to patient, the difference can be absorbed by the free rotation part 124 and the lower leg can be fixed to the lower leg mounting part 125, so that a burden is imposed on the patient. Thus, the above operation can be performed.

In the above description, only the mechanism has been described. However, when the control device for driving the lower limb driving device 100 performs flexible and advanced control, it can be realized by feeding back information on the lower limb. Therefore, as shown in FIG. 2, the thigh motion mechanism 110 and the lower leg motion mechanism 12
At 0, a force detector and an angle detector are provided. The force applied to the thigh is controlled by the free joint 113 and the slide mechanism 11.
4 can be detected by a force detector provided between the free joint 123 and the free rotation part 124. Further, the operation position of the thigh is the first drive shaft 11.
1 and the angle detector 231 that detects the rotation angle of the free joint 113, and the operation position of the lower leg can be detected by the second and third drive shafts 121 and 122.
And the angle detector 233 for detecting the rotation angle of the free joint 123.

FIG. 2 is a diagram showing an example of a control device of the lower limb driving device 100 provided with such sensors, and is a control block diagram utilizing impedance control as force control. In the figure, reference numeral 210 denotes a thigh motion mechanism 110.
Is a control device of the lower leg exercise mechanism. Control device 210 of thigh motion mechanism 110
Is a detector converter 211 that receives and amplifies or processes raw signals of the force detector 230 and the angle detector 231 and converts the signals into a signal corresponding to a force or an angle, an impedance controller 212, and a servo amplifier 213. It is composed of The control of the control device 210 is performed by the thigh motion mechanism 110.
Has a one-degree-of-freedom mechanism, impedance control can be performed using the following equation. Fe = Mαe + BVe + K (θ−θ0) (1) Here, Fe is a force acting between the thigh and the first arm, M,
B and K are the 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, and Ve is the first
The angular velocity of the arm drive shaft (differential value of angle θ), αe is the first
This is the angular acceleration of the arm drive shaft (the second derivative of the angle θ). Since the control using this equation is a known technique, a detailed description will be omitted. In this control system, the force detector 230
And the signal detected by the angle detector 231 is the detector converter 2
When the signal is amplified at step 11 and sent to the impedance control section 212, the impedance control section 212 generates a motion command so as to satisfy the expression (1),
3 to drive the motor of the first drive shaft 111.

The control device 220 of the lower leg exercise mechanism receives the raw signals of the force detector 232 and the angle detector 233, amplifies or processes the signals, and converts the signals into signals corresponding to the force or the angle. 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 lower leg exercise mechanism 120 has two degrees of freedom. Fx = Mαx + BVx + K (x−x0) (2) where Fx is a force acting between the lower leg and the second arm,
M, B, and K are target impedances, x is the position (x, y) of the second arm-free joint, x0 is the equilibrium point of the spring stiffness of x, Ve is the derivative of x, and αe is the second derivative of x. is there. Since the control using this equation is a known technique, a detailed description will be omitted. In this control system, when the force signal and the 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 control unit 222, the impedance control unit 222 performs (2) A motion command is generated so as to satisfy the formula, 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 movement mechanism section 110 and the lower leg movement mechanism section 120 has been described. However, if the control method can be simplified, the detector may be appropriately changed. It may be omitted and reduced.

In the embodiment described above, the lower limb driving device 100 is constituted by the thigh motion mechanism 110 and the lower leg motion mechanism 120.
Can be used alone to provide exercise to the patient's lower limbs. In some cases, the patient needs to exercise the entire lower limb, but in other cases it may be necessary to exercise only the lower leg, and there are individual differences among patients. In the case of a patient who needs to exercise only the lower leg, the lower leg motion mechanism 12 of the present invention is used.
The same operation as that of the lower leg exercise mechanism 120 in the above embodiment is performed using only 0. Therefore, the effect is also as described above.

Next, a modification of the present invention will be described. When the lower limb driving device 100 of the present invention is used, there is a possibility that a patient's body such as a hand may be injured by being pinched by a moving link member. In this modification, as a precautionary measure, a contact sensor is provided on the link member to detect a contact so that an emergency stop can be performed. Therefore, a case where a contact sensor, that is, a touch sensor is mounted will be described with reference to FIG. The figure shows (a) how the touch sensor is attached and (b)
7 shows a simple example of an emergency stop circuit that outputs a signal indicating contact. As shown in (a), the mounting portion of the touch sensor includes upper and lower surfaces of a link member between the drive shaft 111 and the interlocking drive shaft 112, and the drive shaft 121 and the drive shaft 12
5 at the upper and lower surfaces of the link member between the two, and 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 arranged in a cheap place with the limbs sandwiched therebetween, it is possible to easily know when the limbs are sandwiched. Pressed conductive rubber is used for the touch sensor used here, and A and B cord type electrodes are provided in parallel inside, and elastic members such as rubber are sandwiched between them. Have been. When a certain amount of pressure is applied to a part of the part, a short circuit occurs. # 0009b) is an example of an emergency stop circuit of the touch sensor. One end of the touch sensor is pulled up to the HI level (24V),
The other end is dropped to GND (0 V) via a relay control terminal. If the relay is connected in series with the servo-on circuit, when the touch sensor is pressed, the terminals A and B are short-circuited, the terminals of the relay are opened, the servo is cut off, and the motor is stopped. The disconnection at the terminal of the relay is not limited to this, and may be a main power supply or a signal of a speed command. Also, an example in which the touch sensor is provided at five locations of the three link members has been described. However, the location where the touch sensor is provided may be provided at any place where it is considered dangerous, and the touch sensor is not limited to the three link members. 4
It may be provided on all three link members.

[0016]

As described above, according to the present invention, the deviation of the distance between the lower limb driving device and the patient lying down from the proper value and the rotation of the shaft of the lower leg due to the degree of the O leg are absorbed, and Since the lower limb can be driven without imposing a burden on the lower limb, it is possible to provide a highly practical lower limb driving device that is gentle to the patient.

[Brief description of the drawings]

FIG. 1 is a side view showing a lower limb driving device of the present invention.

FIG. 2 is a block diagram including a lower limb driving device and a control device.

FIG. 3 is a diagram showing a modification of the present invention.

FIG. 4 is a side view showing the lower leg drive device of the first conventional example.

FIG. 5 is a side view showing a lower limb driving device of a second conventional example.

[Explanation of symbols]

100, 200, 300, 400, 500 Lower limb driving device 110 Thigh motion mechanism 111, 121, 122, 411, 421, 422, 5
02 Drive shaft 112 Interlocking 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 exercise mechanism part 124 Free rotation part 125 Lower leg mounting part 210, 220 Control Device 211, 221 Detector converter 212, 222 Impedance controller 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 504, 506 Rotation mechanism 507 Mounting part

Claims (6)

[Claims] 1. A lower limb drive controlled by a control device to include a thigh motion mechanism for applying a force to the thigh to rotate the hip joint and a crus exercise mechanism for applying a force to the lower leg to rotate the knee joint. In the apparatus, the thigh motion mechanism is mounted on a base, and is connected to a first drive shaft driven by a motor built in the base by a link member, and the first drive shaft is connected to the first drive shaft by a link member. An interlocking drive shaft mechanically reversely rotated by the same angle in accordance with the rotation of the drive shaft, a rotatable free joint connected to the interlocking drive shaft by a link member, a slide mechanism connected to the free joint, A thigh mounting part fixed to a mechanism, the thigh mounting part fixing the thigh, the lower leg exercise mechanism part is mounted on a base, and a second drive shaft driven by a motor built in the base; Drive shaft and link A third drive shaft connected by a member and driven independently of the second drive shaft by a motor built in the base; and a rotatable free shaft connected to the third drive shaft by a link member. A lower limb driving device, comprising: a joint; a free rotating portion connected to the free joint; and a lower leg mounting portion fixed to the free rotating portion to fix a lower leg. At least one of a force detector of the movement mechanism for the thigh for detecting a force applied to the thigh and a force detector of the movement mechanism for the thigh for detecting a force applied to the lower leg are provided. The lower limb driving device according to claim 1, wherein the information is fed back to the control device. 3. An apparatus according to claim 1, wherein at least one of the thigh motion mechanism and the lower leg motion mechanism for detecting the angle of the free joint is provided, and the information is fed back to the control device. The lower limb driving device according to claim 1, wherein: 4. The device according to claim 1, wherein a touch sensor is provided on a link member of the thigh motion mechanism and the lower leg motion mechanism, and a signal thereof is fed back to the control device. Lower limb drive. 5. A lower limb driving device, the operation of which is controlled by a control device, wherein the lower limb driving device includes a lower leg exercise mechanism for rotating a knee joint by applying force to the lower leg, wherein the lower leg exercise mechanism is mounted on a base, A first drive shaft driven by a motor built in the base, connected to the first drive shaft by a link member, and driven independently of the first drive shaft by a motor built in the base; A second driving shaft, a rotatable free joint connected to the second driving shaft by a link member, a free rotating portion connected to the free joint, and a lower leg fixed to the free rotating portion. A lower limb driving device, comprising: a lower leg mounting portion to be fixed. 6. The control device, wherein at least one of a force detector for detecting a force applied to the lower leg, an angle detector for detecting an angle of a free joint, and a touch sensor is provided in the lower leg exercise mechanism. 6. The lower limb driving device according to claim 5, wherein feedback is provided to the lower leg.