JP2013220333A - Rotational displacement measuring apparatus of living body joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure spatial rotational displacement of a living body joint of 1 freedom degree or 2 freedom degrees or more not exposing a rotation center for all rotating directions to be operated.SOLUTION: For an object joint, by putting gears for setting a virtual line, for which a relative position to the skeletons of both side parts is invariable, on the both side parts of the joint and following spatial displacement of the virtual lines with each other by a link mechanism of 6 freedom degrees connecting the gears, a rotational displacement amount can be simultaneously measured for all the rotating directions of the joint.

Description

The present invention can determine the spatial rotational displacement of a living joint without specifying the rotational center of the joint,
The present invention relates to a mechanism for measuring the amount of spatial rotational displacement.

Measurement of joint movement and range of motion are important in diagnosis, treatment and rehabilitation in orthopedics. In many cases, the measurement uses a simple instrument that measures an in-plane angle such as a combination of a protractor and a ruler. (Non-Patent Document 1)

In orthopedic diagnosis, rehabilitation, and sports training, when measuring the rotational displacement of a joint, it is often assumed that the rotational center is assumed by visual measurement. In many cases, the rotational center of the joint is specified. It is difficult to accurately measure rotational displacement.

Further, with the instrument and the method, it is not possible to measure the motion of a joint having two or more degrees of freedom, such as a hip joint or a shoulder joint, as a spatial rotational displacement that occurs simultaneously with two degrees of freedom.

Even in joints with one degree of freedom such as elbows and knees, an out-of-plane motion of the joint actually occurs, but the conventional joint range-of-motion measurement method cannot measure rotational displacement in the out-of-plane direction. . For joint deformity due to aging, it is useful to accurately measure the rotational movement of the joint in a direction that does not move originally, which is useful for accurately diagnosing the symptoms. It is not possible to measure the rotational displacement in the direction that does not work.

In the Japanese Orthopedic Association, the range of motion of joints is required to investigate the limiting factors of joint range of motion, determine the degree of disability, establish a treatment plan, and proceed with treatment.
According to the Japanese Orthopedic Society display method, the anatomical limb position is set to 0 °, the angle is measured by the axis center (center of the joint), the fixed bar is the fixed axis, and the moving bar is the moving axis. However, since it is extremely difficult to accurately specify the rotation center gauge in the living joint, it is not possible to measure an accurate amount of rotational displacement.

As a known method for measuring the spatial rotational displacement of a joint, there is a method for evaluating the motion of an artificial joint attached to a skeletal model by combining a joint with 6 degrees of freedom and a rotational angle sensor. It is not applicable to living joints. (Patent Document 1)

JP 2007-167318 A

Application of electronic joint range-of-motion measuring device to evaluation of degree of care required Niigata Dental Society Journal 36 (2), 17-24, December 2006 Expert Meeting on Disability Pension Certification (Joint Function etc.) (1st) Minutes December 16, 2011, Ministry of Health, Labor and Welfare

In orthopedic surgery and sports orthopedic surgery, the measurement of the range of motion of the joint is used as the basis for the determination of the treatment method and the effect, but two-dimensional rotation is visually measured using a ruler-like instrument. The problem with this is that
(A) A geometric error occurs due to the inability to accurately grasp the center of rotation. (B) A visual reading error occurs. (C) Spatial rotation cannot be measured. There is no choice but to ignore the rotational displacement in the direction.

As a known method for measuring the spatial rotational displacement of a joint, there is a method for evaluating the motion of an artificial joint attached to a skeletal model by combining a joint with 6 degrees of freedom and a rotational angle sensor. It cannot be applied to living joints. (Patent Document 1)

The present invention solves the above problems.

The present invention
A brace (1) to be worn on both sides of the joint to be measured;
A 6-degree-of-freedom link mechanism (4) for connecting the braces;
A rotation angle detecting device (4c) for measuring the rotational displacement of each degree of freedom in the link mechanism is provided, and virtual lines whose spatial positional relationship is invariable with respect to the skeletons on both sides of the joint to be measured by each of the devices described above are respectively provided. Set,
The 6-degree-of-freedom link mechanism follows the relative displacement of the virtual line,
A rotational displacement measuring device for a biological joint, characterized in that the rotational rotational displacement of both virtual lines is measured by the rotational angle detecting device.

A biological joint is a joint of an organism having an endoskeleton or an exoskeleton.
The imaginary line is set to represent the spatial geometric position of the target joint bilateral skeleton with respect to the joint.
Spatial rotational displacement measurement is to measure the rotational displacement of a joint in a three-dimensional space by breaking it into rotations around three orthogonal axes.
By measuring the relative spatial positional relationship between virtual lines on both sides of the target joint with respect to the rotational movement of the target joint, the spatial rotational displacement can be represented without specifying the rotational center of the target joint. I can do it.

In the present invention,
Attach braces to each side of the target joint,
Set each virtual line whose relative positional relationship with the skeleton is unchanged,
By following the relative displacement between the virtual lines with a link mechanism of 6 degrees of freedom,
The most important feature is to spatially measure the rotational displacement of the joint.

In particular,
Wearing a brace for setting a virtual line whose relative position relative to the skeleton is unchanged on both sides of the target joint (FIG. 1),
Connect the braces on both sides of the joint with a link mechanism (4) with 6 degrees of freedom,
By measuring the rotational displacement of each degree of freedom,
Measure the spatial rotational displacement between virtual lines,
Determine the relative amount of rotational displacement of the skeleton at both sides of the joint.

The brace is
In order to make the relative geometric position unchanged with respect to the skeleton of the wearing part,
Place the buttocks in a place where the influence of muscle movement on the skeleton can be ignored (FIG. 2A),
While the joint is moving, it should be installed so that changes in position relative to the skeleton can be ignored.

Isobe
It is set as a buttock top surface part (2a) which can be stably installed with respect to the skeleton with respect to the installation site, and this is supported by the buttock side surface part (2b).
Depending on the location of the joint to be measured, for the upper and lower limbs, for the trunk, and for the limbs, prepare the hips having the shape and size of the buttocks top surface portion and the buttocks side surface portion for both sides of the target joint.

In addition, in order to install the collar on the appropriate mounting part, the orthosis adjusts the overall length of the orthosis in the longitudinal direction (3c), adjusts the rotation around the longitudinal axis (3d), and adjusts the rotation of the collar around the longitudinal axis of the longitudinal axis ( 3e) is possible.

Connect the braces with a link mechanism with 6 degrees of freedom, follow the spatial displacement of the virtual lines, and measure the amount of spatial rotational displacement of the virtual lines by summing the rotational displacement of each degree of freedom. It can be determined as the amount of spatial displacement of the joint.

By using the present invention,
For living joints where the center of rotation is difficult to identify
Without specifying the center of rotation
It becomes possible to measure the spatial rotational displacement of the living joint.

In orthopedic surgery and sports orthopedic surgery, it was impossible with the conventional method of visually measuring the two-dimensional rotation using a ruler-like instrument.
(A) Measuring geometrically accurate rotational displacement without accurately grasping the center of rotation (a) Eliminating visual reading errors (c) Spatial rotational displacement, in other words, a ruler measuring instrument It becomes possible to measure the rotational displacement in the out-of-plane direction.

In addition, by setting virtual lines with the braces on both sides of the joint, it is possible to apply a spatial rotational displacement measuring method using a link mechanism with 6 degrees of freedom to a living body joint without depending on a method of directly attaching to a skeleton. Become.

Furthermore, since it is possible to simultaneously measure the degrees of freedom of rotational displacement of joints with two or more degrees of freedom, such as shoulder joints and hip joints, which were impossible until now, joint movement when pain or convulsions occur It becomes possible to accurately grasp the state as the rotational displacement, and to accurately grasp the progress of the rehabilitation as the rotational displacement amount of the joint.

In addition, since it is possible to measure the movement of joints, such as knee joints and elbow joints, in a direction outside the degree of freedom of joints, it is necessary to accurately evaluate joint movement abnormalities due to joint deformities etc. as the amount of rotational displacement of joints. Is possible.

In addition, in sports training, it is possible to objectively and accurately perform form guidance based on the joint rotation angle.
In addition, in the study of living organisms having a skeleton and the treatment of pets, it is possible to accurately evaluate joint motion by using an appliance suitable for the subject.

It is the schematic which shows the whole structure of the rotational displacement measuring apparatus of a biological joint. It is a figure of the buttocks which mounts an orthosis on a human body among the rotational displacement measuring apparatuses of a biological joint. (A) Overall view of the buttocks, (B) Cross-sectional view of mounting It is a general view of the brace | limb which fixes a virtual line to the joint both sides site | part among the rotational displacement measuring apparatuses of a biological joint. It is a general view of the link mechanism which connects the orthosis of both sides of a joint among rotation displacement measuring devices of a living body joint. It is the figure which showed the attachment to the arm part of a link mechanism. It is a figure of the joint part in a link mechanism. It is the figure which illustrated the mounting method of the brace of FIG. 1 (elbow) It is the figure which illustrated the mounting method of the orthosis of FIG. 1 (knee). It is the figure which illustrated the mounting method of the brace of FIG. 1 (shoulder) It is the figure which illustrated the mounting method of the orthosis of FIG. 1 (hip joint) It is the figure which illustrated the mounting method of the brace of FIG. 1 (waist) It is the figure which illustrated the mounting method of the brace of FIG. 1 (neck) It is the figure which illustrated the mounting method of the brace of FIG. 1 (wrist) It is the figure which illustrated the mounting method of the orthosis of FIG. 1 (ankle).

Hereinafter, embodiments for carrying out the present invention will be described.

The present invention
A brace (1) to be worn on both sides of the joint to be measured;
A 6-degree-of-freedom link mechanism (4) for connecting the braces;
A rotation angle detecting device (4c) for measuring the rotational displacement of each degree of freedom in the link mechanism is provided, and virtual lines whose spatial positional relationship is invariable with respect to the skeletons on both sides of the joint to be measured by each of the devices described above are respectively provided. Set,
The 6-degree-of-freedom link mechanism follows the relative displacement of the virtual line,
A rotational displacement measuring device for a biological joint, characterized in that the rotational rotational displacement of both virtual lines is measured by the rotational angle detecting device.

The imaginary line is set to represent the spatial geometric position with respect to the joint of the target joint bilateral skeleton.
When the rotational motion of the joint is measured, the spatial rotational displacement of the target joint can be represented by measuring the relative spatial positional relationship between a pair of virtual lines on both sides of the target joint.

The orthosis for setting the imaginary line includes a pair of hooks and an arm that connects the hooks. One of these braces is placed on each side of the target joint (FIG. 1).

In order to make the position of the imaginary line invariable with respect to the skeleton, the both buttocks are installed in a portion that is not easily affected by the movement of the muscle (FIGS. 7 to 15).

The arm portion includes a mechanism (3c) for adjusting the entire length in the longitudinal direction, a mechanism (3d) for adjusting the rotation in the circumferential direction of the longitudinal direction, and a mechanism for adjusting the rotation for installing the collar portion at the position described in the previous section. (3e).

The six-degree-of-freedom link mechanism (4) for connecting the two orthoses is configured by connecting three orthogonal two-degree-of-freedom joints (4b) with their axes connected in parallel (FIG. 4).

A rotation angle detection device (4c) is arranged for each of the six degrees of freedom of the link mechanism. The spatial rotational displacement measurement method using a 6-DOF link mechanism is performed in the same manner as a known method.

When the present invention is used, it is used in the following procedure.

A brace is mounted on each side of the joint so as to straddle the joint to be measured (FIG. 1).

In order to fix and set the imaginary line for the skeleton on both sides of the joint to be measured, the place where the distance to the skeleton is short, that is, the place where the subcutaneous tissue is relatively thin, is installed on both sides. FIG. 2 (B)). The place where the subcutaneous tissue is relatively thin is different for each part of the body as shown in FIGS.

When measuring the rotational displacement of the joint, the measurer fixes one side of the joint on both sides of the subject and performs measurement while operating the other side. The joint of the subject is operated while holding the hand, or is fixed so that the buttocks do not move with an elastic band-like elastic band. Since the rotational displacement detection device has a sufficiently small rotational resistance, it is only necessary to be able to hold the buttocks within a range in which the appliance does not fall off.

In the case of the elbow joint, as shown in FIG. 7, the upper arm is provided with a buttocks near the elbow and between the deltoid muscle and the triceps and anterior saw muscle, and the lower arm is provided near the elbow and the wrist of the radius.

In the case of the knee joint, as shown in FIG. 8, the thigh is set on the body side large bone upper and lower quadriceps ends and the lower leg is placed on the upper and lower tibia.

In the case of the shoulder joint, as shown in FIG. 9, the scapula side is provided with an inner end and an outer end, and the upper arm side is provided near the elbow and between the deltoid muscle and the triceps and anterior saw muscles.

In the case of a hip joint, as shown in FIG. 10, a hip is installed at two points on the outer end of the iliac bone on the lumbar side, and on the thigh at the upper part of the body side and the lower part of the quadriceps.

In the case of the hip movement, as shown in FIG. 11, the hip is provided with two protrusions on the back of the iliac bone, and the upper body is provided with a buttocks on the left and right sides of the scapula.

In the case of cervical movement, as shown in FIG. 12, the head is set at two points on the back of the skull and the upper body is set at two points on the left and right sides of the scapula.

In the case of a wrist joint, as shown in FIG. 13, the upper arm is placed near the elbow and the heel of the deltoid muscle and the triceps and anterior saw muscles, and the hand is placed above and below the metacarpal bone on the back side of the hand.

In the case of an ankle joint, as shown in FIG. 14, the crus are placed on the upper and lower tibias, and the foot is placed on the ribs.

With the angle at the start of operation as an initial value, the rotation angle in the biaxial direction is calculated from the output results of the six rotation detection devices each time the joint is operated.

When measuring from the normal position in the joint range of motion measurement method to the state where the joint is operable, the joint range of motion can be measured as the amount of spatial displacement.

The amount of spatial rotational displacement is measured after being decomposed into two axes with respect to the appliance mounting direction. When measuring the range of motion of the joint, the amount of rotational displacement inside and outside the main motion surface can be calculated by performing coordinate system conversion on the main motion surface of the target joint.

DESCRIPTION OF SYMBOLS 1 Brace | hook 2a Top surface part 2b Side surface part 2c Arm receiving part 3 Arm part 3a Arm shaft 3b Arm joint 3c Arm longitudinal direction full length adjustment mechanism 3d Arm longitudinal direction rotation adjustment mechanism 3e Arm receiving part rotation adjustment mechanism 4 Link mechanism 4a Link arm 4b Link joint 4c Rotational displacement detector A Target joint both sides Cross section of one side buttock installation part A1 Motion measurement target skeleton A2 Motion measurement target skeleton A3 Subcutaneous tissue B buttock installation target position

Claims (4)

A brace attached to both sides of the joint to be measured;
A 6-DOF link mechanism for connecting the braces;
A rotation angle detecting device for measuring the rotational displacement of each degree of freedom in the link mechanism, and setting each virtual line in which the spatial positional relationship is invariable with respect to the skeleton of both side portions of the joint to be measured by each of the above-mentioned devices,
The 6-degree-of-freedom link mechanism follows the relative displacement of the virtual line,
A rotational displacement measuring device for living joints, wherein the rotational angle detecting device measures the spatial rotational displacement of both virtual lines. The orthosis for setting virtual lines on both sides of the joint is composed of a pair of buttocks and an arm part connecting the same, and the hips are located at a place where the influence of the muscular movement can be ignored on the skeleton of both sides of the target joint. 2. The living body according to claim 1, wherein the living body can be adjusted to fix a relative position with respect to the skeleton without being affected by muscles or skin accompanying the movement of the joint. Joint displacement measurement device. The arm portion has a mechanism for adjusting the overall length of the arm portion in the longitudinal direction so that the heel portion can be freely installed at a place where the influence of muscle movement can be ignored with respect to the skeleton on both sides of the target joint, and the circumferential direction in the longitudinal direction 2. The rotational displacement measuring device for a living joint according to claim 1, further comprising a mechanism for adjusting the rotation and a mechanism for adjusting the rotation for installing the buttocks at the position. The buttocks have a shape that allows the buttocks top surface to be in close contact with the installation site so that the influence of the muscular movement can be ignored on the skeleton on both sides of the target joint so that the buttocks can be stably installed. The rotational displacement measuring device for a biological joint according to claim 1, wherein the shape of the surface portion is supported so as not to fall.