JPS6153063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a prosthetic leg control device, and more specifically, a prosthetic leg having an adjusting means such as a friction mechanism, a spring, or a damper for adjusting the stiffness of bending and extending a knee hinge, or The present invention relates to a prosthetic leg control device for a powered prosthetic leg that is motorized by attaching an actuator to the prosthetic leg.

Conventionally, this type of prosthesis has been shown in FIGS. 1 and 2. This is called a LAPOC prosthetic leg, and as shown in Fig. 1, a thigh pipe 3 is connected to a socket 1 of the thigh cut end attachment part via a mounting plate 2, and a lower leg connection is connected to a thigh connection member 4 at the lower end of the thigh pipe 3. A lower leg pipe 6 is connected to the member 5. 7 is a foot part, 8 is a foot joint, and 9 is a cosmetic cover. As shown in FIG. 2, the knee joint, friction mechanism, and spring damper mechanism have a presser foot 11 engaged with a joint 10 of the knee hinge, and an adjustment screw 12 provided on the presser foot 11. The other end of the lever 13 connected to the presser foot 11 is connected to a piston shaft 14 so as to interlock with a piston 15 at the lower end of the piston shaft 14. Reference numeral 16 denotes a small hole provided in the piston 15, which communicates the outside air with the air reservoir 17. 18 is a spring. Figure 2 shows the joint with the knee extended. With this configuration, the lever 13 pushes down the piston 15 when the knee bends, and pulls the piston 15 back when the knee extends again. As a resistance to this bending and stretching, a frictional force by the presser foot 11 acts on the rotating shaft of the joint 10, a spring force by the spring 18, and a viscous frictional force by the air inside the air reservoir 17 going in and out through the pores 16, Provides appropriate spring and damping characteristics for knee bending and extension. However, once these characteristics are set, they cannot be changed in response to various walking conditions, resulting in problems. For example, normally these characteristics are adjusted to a state of slow walking, but if you do this, if you want to walk quickly, your lower legs will not follow your thighs as quickly, making it difficult to walk properly.
In this way, with conventional prosthetic legs, it is not possible to change the spring force, frictional force, etc. according to the walking speed, so the walking cycle is almost determined by the free vibration cycle of the prosthetic leg, and even if you try to walk quickly, the prosthetic leg will not work properly. Since the prosthesis cannot follow, it becomes an obstacle to walking smoothly, which has been a source of strong dissatisfaction among prosthetic leg users.

This invention was made in view of the above-mentioned circumstances, and utilizes the fact that when a prosthetic leg wearer tries to walk quickly, the output of an accelerometer attached to the normal leg becomes larger than when walking normally. The device automatically adjusts the prosthesis to suit high-speed walking by increasing the friction force on the knee hinge in response to this detection signal, making it easier to change the walking speed. The main purpose of this invention is to provide a prosthetic leg control device with a

Another object of the present invention is to control a prosthetic leg by processing the output of an accelerometer attached to a healthy leg in a processing circuit, and operating a means for adjusting the bending/extension stiffness of a knee hinge based on a signal from the processing circuit. The purpose is to provide equipment.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 3, 19 is a healthy leg of a prosthetic leg wearer, and 20 is a prosthetic leg. Accelerometer 2 on healthy leg 19
1 is attached, and this accelerometer 21 and a processing circuit 22 that processes the signal of the accelerometer 21 are connected by a signal line 23. In FIG. 4, a torque motor 24 controls the rotation angle of the adjusting screw 12 in accordance with the signal level of the processing circuit 22, thereby adjusting the pressure of the presser foot 11 on the joint 10. For this purpose, a restoring spring may be installed against the rotation of the screw.

Next, the operation will be explained. Now, when a prosthetic leg wearer wants to walk fast, he swings his healthy leg 19 quickly, so by detecting the peak value of the signal from the accelerometer 21, the intention of the walker can be known.
Then, adjust the presser foot 11 to the level of this peak value.
If the pressure is increased, the friction of the joint 10 will be increased, and the lower leg of the prosthetic leg 20 will quickly follow the upper leg, allowing high-speed walking. When the pedestrian returns to a low walking speed, the peak value of the signal from the accelerometer 21 becomes smaller, the presser foot 11 becomes looser, and the frictional force of the joint 10 becomes a value suitable for low-speed walking.

In the above embodiment, the torque motor 24 was used to adjust the pressure on the presser foot 11, but the pressure on the presser foot 11 can be adjusted by using an electromagnet to press the presser foot 11 and changing the current applied to the electromagnet. It is also possible to adjust. Alternatively, the structure may be configured such that an appropriate load is applied to the vertical movement of the piston shaft 14 by the force of a torque motor, and the same effect can be obtained.

As described above, according to the present invention, since the acceleration of the healthy leg is detected and the frictional force for bending and extending the prosthetic leg is automatically adjusted, it becomes easy to change the walking speed arbitrarily, and the effect is great. There is something.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view of a conventional prosthetic leg, Fig. 2 is a longitudinal sectional view of the main parts, Fig. 3 is a schematic layout diagram of an embodiment of the present invention, and Fig. 4 is a longitudinal sectional view of the main parts. . 3...Thigh pipe, 4...Thigh connecting member, 5...
...Lower leg connection member, 6...Lower leg pipe, 10...Knee hinge joint, 11...Presser foot, 12...
Adjustment screw, 14... Piston shaft, 15... Piston, 16... Pore, 17... Air reservoir, 18...
Spring, 21... Accelerometer, 22... Processing circuit, 2
3...Signal line, 24...Torque motor. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A prosthetic leg control device for a prosthetic leg equipped with an adjusting means for adjusting the stiffness of bending and extending the knee hinge, which includes an accelerometer to be attached to a healthy leg, and a processing circuit that processes signals from the accelerometer. A prosthetic leg control device comprising: an operating means for operating the adjusting means in response to an output signal of the processing circuit. 2. The prosthetic leg control device according to claim 1, wherein the operating means is a torque motor that operates an adjustment screw of a presser foot that engages a joint of a knee hinge. 3. The prosthetic leg control device according to claim 1, wherein the operating means is an electromagnet that adjusts the pressing force of the presser foot that engages the joint of the knee hinge. 4. The prosthetic leg control device according to claim 1, wherein the operating means is a torque motor that applies an appropriate load to the vertical movement of the piston shaft constituting the adjusting means. 5. The prosthetic leg control device according to claim 1, wherein the prosthetic leg is a powered prosthetic leg having an actuator.