JPS599841B2 - Biological angle meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a biological goniometer that measures the bending angle of a joint.

In this type of device, one end of each arm is attached to a container and a rotating shaft of a sensor that can measure the angle of rotation, such as a potentiometer, and both arms are made rotatable and slidable so that the opposite ends are attached to both sides of the joint. It is well known that it has become possible to attach it to living organisms.

However, in the case of this angle meter, the measurement accuracy will decrease unless the axis of rotation of the sensor matches the axis of rotation of the joint and the arm is not attached to the living body accurately.Also, both arms and the sensor are on a predetermined plane, making it flexible. Because of the lack of a joint, it was difficult to measure some joints, and even smaller joints were impossible to measure. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a living body angle meter that can easily and accurately measure the bending angle of a joint at any part of a living body. And this purpose is achieved by the present invention.
One end of the parallel flexible linear body of the book is fixed to each other,
This is solved by measuring the relative displacement of the other free end when bending along the living body. FIG. 1 is a diagram showing the principle of the present invention, and shows a state in which one end of two linear bodies 1 and 1' is fixed and rotated by Θrad.

At this time, if the linear bodies 1, 1' are bent in an arc shape around the center point O, the relative displacement △L at the free end of the linear bodies 1, 1' on the other side is as follows. It becomes like this. △L=L-R1
Θ-(L-R2Θ)=(R2-R1)・ΘHere, L is the length of the linear body 1 and 1 from the starting point to the end of the bend, and R is the length of the linear body 1 and 2 inside from the center point O. R2 is the distance from the center point 0 to the outer linear body 1, or the outer radius.

Therefore, from the previous equation, R2-R is the distance W between the parallel linear bodies 1 and 2, which is always constant, so △L becomes WΘ and Θ
By measuring ΔL, the bending angle of the joint can be measured. Next, embodiments of the present invention will be described based on FIGS. 2 to 4.

A flexible linear body 1 and a ladle are made of a non-stretchable strip-shaped leaf spring material, as an example, and have parallel grooves 2' and 2 shown in FIG.
3 is a fixture for attaching the linear bodies 1, 1' to an arm, for example. One end of the shaped body 1, 1' is fixed together with the guide 2 by a screw 4, and the guide 2 is fixed by a band 5.

10 is a rotary potentiometer for measuring the above-mentioned displacement amount ΔL;
It is fixed to two fixtures 12.

The linear body 1 protrudes from the guide 2 in advance on the side of the ladle fixture 12, and one of them 1 is locked to a ring 14 fitted into the rotating shaft 13 of the potentiometer 10, and the other v is fixed to the fixture 11. has been done. Further, the rotating shaft 13 is urged in the direction of arrow A by a spring (not shown) whose one end is engaged with the fixture 11 and the other end is engaged with the ring 14 so that the linear body 1 does not slacken. When measuring the bending angle θ of the arm joint, for example, by attaching the fixture 3 to the forearm and the fixture 12 to the upper arm, the sides of the linear bodies 1 and 1' are aligned along the arms on both sides of the arm joint. Install.

When bending the arm joint, the linear body 1 with a large rotation radius becomes the linear body 1
', and the rotating shaft 13 rotates in the direction opposite to the arrow A against the spring force. At this time, if the radius of the ring 14 is R3 in FIG. 4, the corresponding rotation angle α of the rotating shaft 13 is as follows. R2-
Therefore, 21 is a constant, and the rotation axis 13R3 rotates in accordance with the bending angle θ of the arm joint, and this rotation angle α can be easily measured from the potential of the potentiometer 10.

When the arm joint is returned to the opposite direction, the rotation axis 1 is rotated by the spring force.
3 immediately absorbs the slack of the linear body 1, and the potential of the potentiometer 10 can faithfully follow any angle change and direction of change of the arm joint without delay. Incidentally, in order to convert the displacement of the linear body 1 into the rotation of the rotating shaft 13, instead of locking the end of the linear body 1 to the ring 14 and applying a spring bias, the ring 14 is made of rubber. The linear body 1 is held between the pressing roller and the ring 14 is replaced with a pinion.
Connecting a rack that meshes with the terminal end of the linear body 1, attaching an arm radially to the spring-biased rotating shaft 13, and engaging a pin attached to the terminal end of the linear body 1 into its linear slot. It is possible.

It is also possible to use a flexible wire as the linear body and to form the guide groove into a corresponding tubular shape. Furthermore, the slider of the sliding potentiometer can be slid linearly without converting the displacement amount ΔL into a rotation amount.

In this case as well, it is conceivable to spring-bias the slider in order to avoid sagging of the linear body. It is also possible to use other elements such as a variable capacitor as a sensor for the displacement amount ΔL.
The dimensions of the fixture can be changed depending on the joint to be measured, and various fixtures can be attached to and removed from the linear body as desired. As is clear from the above description, the goniometer of the present invention, which measures the relative displacement of one end of two wires, bands, etc., has a simple structure and can be used to measure linear objects other than the sensor and joint parts. Since accurate positioning of the sensor is no longer necessary, the measurement work is also simplified.

Furthermore, it becomes easy to measure the bending angle of small joints such as fingers, which do not require positioning the sensor at the joint and can be located outside the living body.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is an example of a biological goniometer according to the present invention, Fig. 3 is a sectional view thereof, and Fig. 4 is a principle diagram of the sensor of the biological goniometer according to Fig. 2. shows. 1, 1': linear body, 2: guide, 3, 12: fixture, 1
0: Potentiometer.

Claims (1)

[Claims] 1 Two flexible linear bodies and these two at one end.
Detecting the amount of displacement between a flexible guide that fixes one end of the book linear body and holds the two books so that they can slide in parallel with an interval W, and the two linear bodies. and a sensor disposed on the other end side of the guide, the guide is attached along the living body on both sides of the joint to be measured, and the bending angle Θ of the joint is measured from the detected displacement WΘ. angle meter.