JP2002355236A - Method to measure joint angle using biaxial acceleration sensor and electric stimulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method to measure a joint angle by assuming the joint angle by a two-dimensional acceleration sensor put on a body and an electric stimulator capable of giving electric stimulation to muscles of a lost function of a disabled person at good timing in a required period. SOLUTION: This is a method to measure a joint angle using an acceleration sensor. Two dimensional acceleration sensors 1a-1f to measure acceleration are mounted on a body. A microprocessor comprising an input means to receive two-dimensional acceleration signals in the X-axis direction and the Y-axis direction or the X-direction and the Z-axis direction from biaxial acceleration sensors, a time pattern processing means to process the acceleration signals as time elapses into patterns, a predicting means to analyze patterns from the time pattern processing means to predict motion of the thigh part 4, and an output means to output electric stimulation from the predicting means at timing when a foot leaves a floor processes signals to measure and detect estimates of joint angles and timing of body motion such as foot contact, heel- off, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
TECHNICAL FIELD The present invention relates to a joint angle measuring method for estimating a joint angle using a three-dimensional acceleration sensor and an electric stimulator for contracting or expanding a muscle paralyzed by a disease, an accident or the like by applying an electric stimulation to the muscle.

[0002]

2. Description of the Related Art Conventionally, a muscular strength enhancer for performing electrical stimulation is known from Japanese Patent Application Laid-Open No. 2000-279536. In the above publication, as shown in FIG. 5, a thigh orthosis 7 and a lower thigh orthosis 8 are connected by a goniometer 9, and two electrodes are provided inside a thigh base 10. Parts 40 and 41 are provided,
A muscle strength enhancer K that transmits information from a sensor 31 that detects the angle of the goniometer 9 to a controller 42 and supplies electricity to the electrode units 40 and 41 to provide electrical stimulation to muscles. This is when the muscle that is the driving muscle is contracting,
By applying electrical stimulation to the muscle that becomes the antagonist muscle, the antagonist muscle can be exercised by a closed kinematic chain accompanying efferent contraction, and can be used for maintaining or enhancing its muscle strength. is there. In addition, by using the muscle augmenter, the active muscles of the elderly, disabled, weak or paralyzed patients cannot be passively moved (consciously). It can also be intensively strengthened. However, the above-mentioned muscular strength enhancer is not intended for the purpose of reconstructing lost functions of persons with disabilities, which provides electrical stimulation to muscles in a timely manner when necessary.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a joint angle measuring method for estimating a joint angle by a two-dimensional acceleration sensor attached to a body and a timing required for a lost function of a disabled person. It is an object of the present invention to provide an electrical stimulator capable of applying electrical stimulation to the muscle.

[0004]

For this purpose, a joint angle measuring method using an acceleration sensor according to the present invention comprises: attaching a two-dimensional acceleration sensor for measuring acceleration to a body; Input means for receiving a two-dimensional acceleration signal in the Y-axis direction, X-axis direction, or Z-axis direction; time pattern processing means for processing the acceleration signal over time to form a pattern; and analyzing a pattern from the time pattern processing means The processing is performed by a microprocessor including prediction means for predicting the movement of the thigh and output means for outputting electrical stimulation from the prediction means at a timing when the foot leaves the floor. It measures and detects the timing of body movements such as contact and heel-off. Further, the electric stimulator using the acceleration sensor according to the present invention has a two-dimensional acceleration sensor for measuring acceleration attached to the body, and the X-axis, Y-axis direction or X-axis from the two-axis acceleration sensor.
Input means for receiving a two-dimensional acceleration signal in the axial and Z-axis directions, time pattern processing means for processing the acceleration signal over time to form a pattern, and analyzing the pattern from the time pattern processing means to obtain a thigh And a microprocessor comprising output means for outputting electrical stimulation from the prediction means at the timing when the foot leaves the floor, and an electrode inserted so as to reach the stimulation point of the paralyzed muscle of the muscle. It is connected to the microprocessor.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As one embodiment of the electric stimulator using a two-dimensional acceleration sensor of the present invention, as a lost function of a disabled person, the toes can remain down and walking without the help of a walking stick or the like. The following is a description of the case of a non-cuspid leg. Equine footsteps, a common sequela of stroke, result from paralysis of the muscles that raise the toes of the feet. Therefore, the muscles may be contracted by electrical stimulation at a necessary time during walking. The electrical stimulator required for this is to predict when to start the stimulation and to properly contract the selected muscle.

Accordingly, an electric stimulator using the two-dimensional acceleration sensor of the present invention will be described with reference to FIG. 1a,
1b is a two-axis acceleration sensor, in the X-axis, Y-axis direction or X-axis,
It outputs a two-dimensional acceleration signal in the Z-axis direction,
A battery (not shown) and a microprocessor 2 for creating a stimulation pattern are attached to the outside of the thigh 4 by a fixing means 3 such as a band.

The microprocessor 2 has an input means for receiving two-dimensional acceleration signals from the two-axis acceleration sensors 1a and 1b in the X-axis and Y-axis directions or in the X-axis and Z-axis directions, and processes the acceleration signals with time. Time pattern processing means for performing patterning, and a prediction means for analyzing the pattern from the time pattern processing means to predict the movement of the thigh 4; Output means for outputting. The prediction means constitutes an information processing mechanism called a neural network, and has a function of adapting to a user and adapting to a change.

Then, an electrode (not shown) inserted so as to reach the stimulating point of the paralyzed muscle of the thigh 4 is connected to the microprocessor 2.

Next, a data processing system of an electric stimulator using the acceleration sensor of the present invention will be described with reference to FIG. X-axis, Y-axis or X-axis, Z-axis two-dimensional acceleration signals from the two-axis acceleration sensors 1a and 1b attached to the thighs 4 are transmitted to the microprocessor 2, and the two-dimensional acceleration signals are transmitted. The received microprocessor 2 applies an electric stimulus to an electrode (not shown) inserted so as to reach a stimulating point of the paralyzed muscle of the thigh 4 at a stimulating timing that can be predicted by tracing a temporal change of the acceleration signal. Is output. Thereby, the muscles are contracted by applying electrical stimulation at a necessary time during walking. By extending this, it is possible to estimate not only the heel-off timing of the equicuspid disorder but also the angle of the knee joint. FIG. 3 and FIG. 4 show the comparison between the prediction of the operation timing, the estimation of the foot switch and the knee joint angle, and the goniometer. What has been described above is a technique that is realized by two things: a person performs an operation in a predetermined pattern according to a purpose, and walking is an operation in which substantially the same pattern is repeated. Also, as shown in FIG. 1, the acceleration sensors 1c, 1d, and 1e can measure various joint angles of the body when they are mounted on various parts of the body. And many other applications.

[0010]

[Effects] The joint angle measuring method of the present invention can be applied to a body worn on a body.
The joint angle can be estimated by the three-dimensional acceleration sensor, particularly by a process such as a neural network. The electric stimulator using the two-dimensional acceleration sensor of the present invention enables a person who has ever needed a cane to walk without a cane. Also, by attaching a two-dimensional acceleration sensor to various parts of the body, it can be applied to support other than walking.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an electric stimulator using an acceleration sensor of the present invention.

FIG. 2 is a configuration diagram of a data processing system of a microprocessor according to the present invention.

FIG. 3 is a graph showing a prediction of a timing at which a foot separates from a floor;

FIG. 4 is a graph showing an estimation of a knee joint angle.

FIG. 5 is an explanatory view of a conventional muscular strength enhancer.

[Explanation of symbols]

 1a acceleration sensor (thigh) 1b acceleration sensor (thigh) 1c acceleration sensor (arm) 1d acceleration sensor (chest) 1e acceleration sensor (arm) 2 microprocessor 3 fixing means 4 thigh

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyomi Iizuka 80-1 Hiromi Ikari, Akita City, Akita Prefecture Inside Biotech Co., Ltd. (72) Inventor Goro Oinata 1-7-1, Sakuragaoka, Akita City, Akita Prefecture (72) Invention Person Yoichi Shimada 3-10-17 Sakuragaoka, Akita City, Akita Prefecture (72) Inventor Jun Nakayama 42, Nukazuka, Yanagita Character, Akita City, Akita Prefecture 3-204 (72) Inventor Kiyoshi Nagasaku 4-2 Ushijima Nishi, Akita City, Akita Prefecture 24 (72) Inventor Shigeru Ando 9-1-305 Hiromen, Hiruma, Akita-shi, Akita (72) Inventor Yoshihiro Abe 2 F0-term (reference) 2F069 AA71 BB40 HH30 4C038 VA12 VB14 VC20

Claims (2)

[Claims] 1. An input means for wearing a two-dimensional acceleration sensor for measuring acceleration on a body, and receiving a two-dimensional acceleration signal in the X-axis, Y-axis direction or X-axis or Z-axis direction from the two-axis acceleration sensor. A time pattern processing means for processing the acceleration signal over time to form a pattern, a prediction means for analyzing a pattern from the time pattern processing means to predict the movement of the thigh, and a timing at which the foot leaves the floor. An acceleration sensor for measuring and detecting the timing of a joint motion, such as an estimated value of a joint angle, a foot contact, or a heel-off, by processing with a microprocessor including an output unit that outputs an electrical stimulus from the prediction unit. Method for measuring joint angles using a computer. 2. An input means for wearing a two-dimensional acceleration sensor for measuring acceleration on a body, and receiving a two-dimensional acceleration signal in the X-axis, Y-axis direction or X-axis, Z-axis direction from the two-axis acceleration sensor. A time pattern processing means for processing the acceleration signal over time to form a pattern, a prediction means for analyzing a pattern from the time pattern processing means to predict the movement of the thigh, and a timing at which the foot leaves the floor. A microprocessor comprising output means for outputting an electrical stimulus from the prediction means, and an acceleration sensor characterized by connecting an electrode inserted so as to reach a stimulation point of a paralyzed muscle of the muscle to the microprocessor. Electric stimulator.