JPS6213017B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a prosthetic leg that is used by a disabled person who has had one leg amputated at the thigh due to illness, work accident, traffic accident, etc., and in particular a powered prosthetic leg that drives the knee joint with a hydraulic drive device. It is related to.

Conventionally, this type of device has a socket a into which the cut end is inserted as shown in FIG. There is a prosthetic leg connected through the

In this prosthetic leg, the person walks by swinging the lower leg d around the knee joint member e with the foot c as a pendulum, and after the foot c lands on the ground, the user puts his weight on the prosthetic leg.

However, in this case, the walking speed was determined by the mass of the foot and the period of the pendulum depending on the length of the lower leg, so it was not possible to change the walking speed. In addition, if the force applied to the knee joint member is not on the same line as the lower leg, the knee joint member will rotate and cause what is called a mid-fold.
People with prosthetic legs will continue to transition. Therefore, there is a drawback that it is not possible to go up and down stairs and slopes.

In order to solve the drawbacks of this prosthetic leg, a power prosthetic leg as shown in FIG. 2 was developed in which the joint of the knee joint member is hydraulically driven.

This prosthesis consists of a socket B with a myoelectrode A into which the cut end is inserted, and a thigh D with a battery C as a power source.
The thigh D is connected to the lower leg G having a hydraulic pump E and a hydraulic pressure accumulator F via a knee hydraulic drive device I provided with a control circuit H. The part G and the foot part J are connected via an ankle hydraulic drive device K.

Therefore, the electrode A detects myoelectric signals corresponding to walking modes such as walking on flat ground and walking on stairs, and sends this detection signal to the control circuit H, which controls each walking mode in advance according to the signal. An operation pattern of the knee hydraulic drive device I that has been stored in correspondence is selected, and the knee hydraulic drive device I is driven in accordance with the pattern signal to perform walking.

However, with this powered prosthetic leg, when going up and down stairs, even when the difference in steps is small, the knee joints are opened wide to create a pattern to prevent tripping, resulting in an unnatural gait when walking on stairs and a slow walking speed. There is a drawback.

The present invention is intended to eliminate the above-mentioned drawbacks of the conventional method.When going up and down stairs, the knee joint angle is determined for the next step by referring to the landing state of the prosthetic leg in the previous step, so that the gait is natural and fast. The purpose is to be able to go up and down stairs at walking speed.

Hereinafter, one embodiment of the powered prosthetic leg according to the present invention will be described in detail with reference to the attached FIG. 4.

Reference numeral 1 denotes a socket into which the cut end is inserted, and is integrated with a thigh 3 equipped with a battery 2 as a power source. The thigh part 3 is connected to a lower leg part 6 having a hydraulic pump 4 and a hydraulic pressure accumulator 5 via a knee hydraulic drive device 9 having a control circuit 7 and a knee angle sensor 8. The knee is opened by driving the device 9, and the knee angle is detected by the knee angle sensor 8 and controlled by the control circuit 7. Further, the lower leg portion 6 is connected to a foot portion 11 provided with a sole sensor 10 via an ankle drive device 12.

The socket 1 has an electrode 13 for detecting myoelectric signals,
13' is provided.

As is clear from the above configuration, the present invention provides an electrode 1
3 and 13' detect myoelectric signals corresponding to walking modes such as walking on flat ground and walking on stairs, and send this signal to the control circuit 7. As shown in the diagram in the figure, the control circuit 7 detects the point in time when the walking mode switches to stair walking based on the signals from the electrodes 13 and 13', and the first step of the prosthetic leg causes the knee joint angle to move significantly. The knee hydraulic drive device 9 is driven as shown in FIG.
Read with Then, the angle of the knee joint suitable for walking on stairs is detected based on the signal of this knee angle sensor 8.
Based on this, the angle of the knee joint driven by the hydraulic drive device during the next walk is calculated, and a walking pattern of the prosthetic leg suitable for subsequent walking is determined. In other words, when it receives a signal to change the walking mode, it detects the actual angle of the knee joint when the prosthetic leg touches the ground during the first step, stores the knee joint angle suitable for the walking mode based on this angle, and Subsequent walking is controlled based on memory.

In the above embodiment, the walking mode signal was obtained from the myoelectrode, but the same effect can be obtained even if the manual switch is turned on when the device is worn.

As described above, in the present invention, when going up and down stairs, the knee joint angle for the second and subsequent steps is determined by referring to the knee joint angle for the previous step, so that the gait becomes natural and the walking speed increases. You can also get the effect of speeding up the process.

[Brief explanation of the drawing]

The drawings show a powered prosthetic leg according to the present invention, in which Figure 1 is a side view of a conventional powered prosthetic leg, Figure 2 is a perspective view of a conventional powered prosthetic leg, and Figure 3 is a perspective view of the powered prosthetic leg of the present invention. FIG. 4 is a block diagram showing the operation of the control circuit. 1 - socket, 2 - battery, 3 - thigh, 4 - hydraulic pump, 5 - hydraulic pressure accumulator, 6 - lower leg, 7 -
Control circuit, 8-knee angle sensor, 9-knee hydraulic drive device, 10-sole sensor, 11-foot section, 12-drive device, 13, 13'-electrode.

Claims (1)

[Claims] 1. A powered prosthetic leg with a hydraulic drive device installed in the knee joint, which includes a determining means for determining the walking mode, a first detecting means for detecting the knee joint angle, and a second detecting means for detecting the contact of the foot with the ground. and a control means for receiving the signal from the determining means to set the drive angle of the hydraulic drive device, and for receiving both the detection signals and calculating the knee joint angle of the walking pattern.