JP2016041176A - Muscle tonus measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a muscle tonus measuring device that can objectively evaluate presence or absence of contracture.SOLUTION: Joint torque and a joint angle obtained when a joint of a subject 2 is passively subjected to flexion and extension exercise are detected by a detection unit 10. In a coordinate system assuming the joint angle as a horizontal axis and assuming the joint torque as a vertical axis, a range of the joint angle where an angle-torque characteristic graph 80 showing a change of the joint torque to the joint angle has the joint torque larger than a straight line 82 connecting both ends of the angle-torque characteristic graph 80 is assumed as an excessive joint torque range 83. A calculation unit 50 calculates at least one of an area A of a region surrounded by the angle-torque characteristic graph 80 and the straight line 82 in the excessive joint torque range 83, and a maximum distance D between the angle-torque characteristic graph 80 and the straight line 82 in the excessive joint torque range 83, about at least one of a dynamic flexion phase and a dynamic extension phase.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a muscle tonus measuring apparatus that makes it possible to measure and objectively evaluate muscle tonus characteristics.

  Spasticity that develops when muscle tonus is elevated is one of the movement disorders that develops due to various pathological conditions such as cerebrovascular disorders, head trauma, anoxic encephalopathy, spinal cord injury, and multiple sclerosis. . As a characteristic phenomenon of spasticity, when the joint is flexed or extended passively, resistance is recognized at the initial or final stage of movement, and otherwise the resistance decreases or disappears (generally called “jackknife phenomenon”). Called). Currently, MAS (Modified Ashworth Scale) is known as an evaluation index of spasticity widely used in clinical practice. However, since this evaluation method is based on the resistance (resistance) felt by the doctor, the standard is semi-quantitative and the objectivity is poor.

  Patent Documents 1 and 2 describe a muscle tonus measuring device that obtains a spring coefficient of a joint when a subject's joint is flexibly extended and extended. The spring coefficient has a correlation with UPDRS (Unified Parkinson Disease Rating Scale), which is an evaluation index of muscle stiffness found in Parkinson's disease patients. For this reason, this apparatus is useful for objectively evaluating the presence or absence and the severity of muscle stiffness found in Parkinson's disease patients.

International Publication No. 2009/154117 Pamphlet International Publication No. 2011/145465 Pamphlet

  The devices described in Patent Documents 1 and 2 described above are useful for objective evaluation of muscle rigidity, but are not suitable for objective evaluation of spasticity. An apparatus capable of objectively quantitatively evaluating spasticity is desired.

  An object of the present invention is to provide a muscle tonus measuring apparatus that makes it possible to objectively evaluate the presence or absence of spasticity.

  The muscle tonus measuring apparatus of the present invention calculates a joint torque of the joint and a joint angle of the joint when the joint of the subject is flexibly extended and extended, and calculates a signal from the detector And a processing unit for processing. In a coordinate system in which the joint angle is the horizontal axis and the joint torque is the vertical axis, the angle-torque characteristic graph showing the change of the joint torque with respect to the joint angle is larger than the straight line connecting both ends of the angle-torque characteristic graph. When the range of joint angles having joint torque is an excessive joint torque range, the calculation unit includes an area of a region surrounded by the angle-torque characteristic graph and the straight line in the excessive joint torque region, and At least one of the maximum distance between the angle-torque characteristic graph and the straight line in the excessive joint torque region is calculated for at least one of the dynamic flexion phase and the dynamic extension phase.

  The muscle tonus measuring apparatus according to the present invention includes an area of a region surrounded by an angle-torque characteristic graph and a straight line in the excessive joint torque region, and a maximum distance between the angle-torque characteristic graph and the straight line in the excessive joint torque region. At least one of the above. Both the area and the maximum distance correlate with the sense of resistance that the doctor feels when the patient's joint is flexed and extended. Therefore, the presence or absence of spasticity can be objectively evaluated by using the muscle tonus measuring apparatus of the present invention.

FIG. 1 is a diagram showing a schematic configuration of a muscle tonus measuring apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a change in joint torque with respect to a joint angle in a dynamic extension phase of an elbow joint of a healthy person (MAS is 0). FIG. 3 is a diagram illustrating an example of a change in joint torque with respect to a joint angle in a dynamic extension phase of an elbow joint of a patient having spasticity (MAS is 2). FIG. 4 is a diagram showing an example of a change in joint torque with respect to the joint angle in the dynamic extension phase of the elbow joint on the healthy side (the side without paralysis) of the stroke patient.

  In the muscle tonus measuring apparatus of the present invention, it is preferable that the calculation unit calculates at least one of the area and the maximum distance for both the dynamic flexion phase and the dynamic extension phase. According to such a preferable configuration, the presence or absence of spasticity can be more accurately evaluated.

  In the coordinate system, a joint angle of an end having a small joint angle among both ends of the angle-torque characteristic graph is a minimum joint angle, a joint angle of an end having a large joint angle is a maximum joint angle, and the minimum joint angle and the The difference from the maximum joint angle is defined as a bendable / extendable range, the joint angle larger than the minimum joint angle by 10% of the bendable / extendable range is defined as the first joint angle, and the joint is smaller than the maximum joint angle by 10% of the bendable / extendable range. When the angle is the second joint angle, the calculation unit calculates the first distance between the first point on the straight line having the first joint angle and the angle-torque characteristic graph, and the second joint angle. The second distance between the second point on the straight line and the angle-torque characteristic graph is preferably calculated for at least one of the dynamic flexion phase and the dynamic extension phase. According to such a preferable configuration, it is possible to objectively evaluate whether or not an example determined to have no spasticity (MAS is 0) on examination has slight spasticity.

  In the above, it is preferable that the calculation unit calculates the first distance and the second distance for both the dynamic flexion phase and the dynamic extension phase. According to such a preferable configuration, it is possible to more accurately evaluate whether or not an example determined to have no spasticity (MAS is 0) on examination has slight spasticity.

  The calculation unit may obtain the angle-torque characteristic graph by approximating a change in the joint torque with respect to the joint angle by a cubic function. Such a preferable configuration is advantageous in improving the evaluation accuracy by eliminating the influence of noise and reducing the burden when performing the arithmetic processing of the arithmetic unit.

Spasticity can be evaluated using the muscle tonus measuring apparatus of the present invention. The method for evaluating spasticity according to the present invention comprises:
(1) attaching a detector for detecting joint torque and joint angle to the subject's joint;
A step (2) of flexibly extending and extending the joint of the test subject,
A step of obtaining an angle-torque characteristic graph showing a change in the joint torque with respect to the joint angle in a coordinate system having the joint angle on the horizontal axis and the joint torque on the vertical axis from the joint torque and the joint angle obtained from the detection unit ( 3) and
In the coordinate system, when a joint angle range having a joint torque larger than a straight line connecting both ends of the angle-torque characteristic graph is an excessive joint torque region, the angle-torque characteristic graph in the excessive joint torque region and the At least one of the area surrounded by the straight line and the maximum distance between the angle-torque characteristic graph and the straight line in the excessive joint torque region is the dynamic flexion phase and the dynamic extension phase. And (4) calculating at least one of the above.

  The evaluation method may further include a step (5) of evaluating the presence or absence of spasticity using at least one of the area and the maximum distance.

  The step (5) can be performed by comparing at least one of the area and the maximum distance with a predetermined reference value.

  In the evaluation method, the step (3) may include a step of obtaining the angle-torque characteristic graph by approximating a change in the joint torque with respect to the joint angle by a cubic function.

  Below, this invention is demonstrated in detail, showing suitable embodiment. However, it goes without saying that the present invention is not limited to the following embodiments. For convenience of explanation, the drawings referred to in the following description show only the main members necessary for explaining the present invention in a simplified manner among the members constituting the embodiment of the present invention. Therefore, the present invention can include any member not shown in the following drawings. Further, in the following drawings, the actual dimensions of members and the dimensional ratios of the members are not faithfully represented.

  FIG. 1 is a diagram showing a schematic configuration of a muscle tonus measuring apparatus according to an embodiment of the present invention. This device is used to detect the joint torque and joint angle of the elbow joint when the elbow joint of the subject 1 is dynamically flexed and extended, and to evaluate the presence or absence of spasticity.

  The muscle tonus measuring apparatus detects a joint torque of the elbow joint and a joint angle of the elbow joint when the elbow joint of the subject 1 is flexibly extended and extended, and an output signal from the detection unit 10. And an arithmetic unit 50 that performs arithmetic processing. As shown in FIG. 1, the detection unit 10 is attached to the wrist joint of the subject 1 so as to sandwich the detection unit 10, and the examiner 2 flexes and extends the elbow joint of the subject 1 through the detection unit 10.

  The detection unit 10 includes a base 11 having a substantially U shape or a substantially U shape.

  A pair of force sensors 20a and 20b are fixed to a pair of sandwiching plates 12a and 12b of the base 11 facing each other so as to face each other. If the direction in which the pair of force sensors 20a and 20b face each other is the Z axis, the force sensors 20a and 20b detect at least a force (compression force) in the Z axis direction. As the force sensors 20a and 20b, the structure is not limited as long as the compressive force applied to the force sensors 20a and 20b can be detected. For example, conventionally known general-purpose force sensors can be used. The force sensors 20a and 20b may be uniaxial force sensors that detect only forces in the Z-axis direction, and are triaxial force sensors that detect forces in three axial directions that include the Z axis and are orthogonal to each other. May be. In addition to the force in the Z-axis direction, by detecting the force in the biaxial direction perpendicular to the Z-axis direction, the direction of the force applied to the subject 1 by the examiner 2 can be corrected, or the detected Z-axis direction Force data can be corrected. In order to alleviate the pain caused by the force sensors 20a and 20b coming into direct contact with the skin of the subject 1 during the flexion and extension movement of the elbow joint, the opposing surfaces of the force sensors 20a and 20b (the hands of the subject 1) A flexible pad may be affixed to the surface abutting the joint portion.

  A gyro sensor 30 is fixed to the bridging plate 13 that connects the pair of sandwiching plates 12 a and 12 b of the base 11. The gyro sensor 30 detects a change in posture of the detection unit 10 including the gyro sensor 30 that changes in accordance with the flexion and extension motion of the elbow joint of the subject 1. The fixed position of the gyro sensor 30 is not limited to the bridge plate 13 and may be an arbitrary position of the base 11.

  An adjustment mechanism (not shown) that makes it possible to change the distance between the pair of sandwiching plates 12a and 12b in accordance with the thickness of the joint of the subject 1 is provided in order to improve the wearability to the subject 1. May be provided. Such an adjustment mechanism is not limited. For example, a slide mechanism that allows the sandwiching plate 12a and / or the sandwiching plate 12b to move in the Z-axis direction with respect to the bridging plate 13, and the sandwiching plate 12a and / or the sandwiching plate 12b. A hinge mechanism or the like that enables the bridge plate 13 to be inclined at an arbitrary angle can be appropriately employed. Alternatively, the base 11 may be a rigid body that does not include the adjustment mechanism and cannot be substantially deformed.

  When bending and extending the elbow joint of the subject 1, the detection unit 10 moves along an arc centered on the elbow joint. During the flexion and extension movement of the elbow joint, the posture of the detection unit 10 is maintained so that the Z axis is always parallel to the tangential direction of the arc. The force sensors 20a and 20b output a voltage corresponding to the force in the Z-axis direction that the examiner 2 applies to the subject 1 when the examiner 2 performs flexion and extension movement of the elbow joint of the subject 1. The voltages output from the force sensors 20 a and 20 b are amplified by the force sensor amplifier 21 as necessary, and then input to the arithmetic unit 50 via the A / D conversion board 51. A voltage output from the gyro sensor 30 and corresponding to the change in posture is input to the arithmetic unit 50 via the A / D conversion board 51.

  The calculation unit 50 determines the distance between the force in the Z-axis direction detected via the force sensors 20a and 20b and the elbow joint of the subject 1 measured separately and the mounting position of the detection unit 10 (that is, the bending extension motion). The joint torque is calculated from the radius of the arc that the detection unit 10 moves. In calculating the joint torque, it is preferable to perform correction by gravity. In addition, the calculation unit 50 calculates the joint angle by integrating the posture change (angular velocity) of the detection unit 10 detected via the gyro sensor 30. Further, the calculation unit 50 performs a predetermined calculation process (details will be described later) from these temporal changes in the joint torque and the joint angle.

  As the calculation unit 50, for example, a general-purpose personal computer can be used. Data related to temporal changes in joint torque and joint angle, data obtained by performing arithmetic processing on these, and the like may be stored in a storage device as necessary. The storage device may be built in the calculation unit 50 or may be provided outside the calculation unit 50.

  An output device 52 may be connected to the calculation unit 50. As the output device 52, for example, various displays and printers can be used. The output device 52 displays the result calculated by the calculation unit 50.

  As shown in FIG. 1, the examiner 2 flexes and extends the elbow joint of the subject 1 through the detection unit 10 while the detection unit 10 is mounted on the wrist joint of the subject 1. While repeating the four phases of (1) maximum extension position stationary, (2) dynamic flexion, (3) maximum flexion position stationary, and (4) dynamic extension, Measure joint angles. The rate of change (angular velocity) of the joint angle of the elbow joint in the dynamic flexion phase and the dynamic extension phase is assumed to be substantially constant. The angle range of bending extension can be changed according to the subject 1.

  FIG. 2 is a diagram illustrating an example of a change in joint torque with respect to a joint angle in a dynamic extension phase of an elbow joint of a healthy person (MAS is 0). In FIG. 2, the horizontal axis represents the joint angle (radian), and the vertical axis represents the joint torque (N · m). The joint angle on the horizontal axis is expressed as a bending angle with respect to a state where the joint is extended. Therefore, the left side of FIG. 2 shows the extension side, and the right side shows the bending side.

  A solid line 70 indicates actual measurement data of a change in joint torque with respect to a joint angle. The left end of the solid line indicates the maximum extended position (the elbow joint is most extended) 70e, and the right end of the solid line indicates the maximum bent position (the elbow joint is most bent) 70f. Arrows indicate changes in time. Therefore, the solid line 70 shows the change of the joint torque with respect to the joint angle in the dynamic extension phase in which the elbow joint is extended at a substantially constant speed from the maximum bending position 70f to the maximum extension position 70e.

  A broken line 71 is a cubic function approximation graph obtained by approximating the solid line 70 with a cubic function.

  An alternate long and short dash line 72 is a straight line connecting both ends of the solid line 70 (that is, the maximum extended position 70e and the maximum bent position 70f).

  In the present invention, as shown in FIG. 2, a graph (solid line 70 and broken line 71) showing changes in joint torque with respect to the joint angle in a coordinate system with the joint angle as the horizontal axis and the joint torque as the vertical axis is expressed as “angle− "Torque characteristic graph". In the following description, in order to distinguish between the two angle-torque characteristic graphs 70 and 71, the angle-torque characteristic graph (solid line 70) showing the measured data is referred to as "measured graph", and is an angle approximated by a cubic function- The torque characteristic graph (broken line 71) is referred to as a “cubic function approximation graph”.

  As shown in FIG. 2, in a normal person, generally, the graphs 70 and 71 are located below the straight line 72 and have a curved shape that is convex downward macroscopically (however, on the upper side) It may partially contain a convex curve shape).

  FIG. 3 is a diagram showing an example of a change in joint torque with respect to the joint angle in the dynamic extension phase of the elbow joint of a patient with spasticity (MAS is 2), as in FIG. This patient is judged to have spasticity (MAS is 2) in order to feel obvious hypertonia in the entire range of motion.

  A solid line 80 is an actual measurement graph showing actual measurement data of a change in joint torque with respect to the joint angle. A broken line 81 is a cubic function approximation graph obtained by approximating the solid line 80 with a cubic function. An alternate long and short dash line 82 is a straight line connecting both ends of the solid line 80 (that is, the maximum extended position 80e and the maximum bent position 80f). Arrows indicate changes in time.

  As shown in FIG. 3, in a patient having spasticity, in general, a part of the graphs 80 and 81 is located above the straight line 82 and the remaining part is located below the straight line 82. To do. When viewed macroscopically, the portion of the graphs 80 and 81 that is located above the straight line 82 has a curved shape that is convex upward, and the portion of the graphs 80 and 81 that is located below the straight line 82 is , Has a convex curve shape on the lower side.

  As described above, the change rate (angular velocity) of the joint angle in the dynamic extension phase is substantially constant. Therefore, the “joint angle” on the horizontal axis in FIGS. 2 and 3 can be read as “time”. In this case, the area of the region surrounded by the angle-torque characteristic graph and the horizontal axis corresponds to “impulse” for extending the elbow joint. This impulse is the “resistance” felt when the examiner 2 extends the elbow joint of the subject 1. As can be easily understood by comparing FIG. 2 and FIG. 3, the macroscopic shape of the angle-torque characteristic graphs 80 and 81 in FIG. 3 is the “jackknife phenomenon” which is a characteristic phenomenon of spasticity. Matches very well with the resistance felt by 2.

  The inventors focused on the fact that the shape of the angle-torque characteristic graph differs between FIG. 2 (without spasticity) and FIG. 3 (with spasticity) as described above. In particular, the inventors focused on the fact that, in FIG. 3, a part of the angle-torque characteristic graph 80 protrudes above a straight line 82 connecting both ends thereof. The inventors have found that the presence or absence of spasticity can be objectively identified by using an index that quantitatively indicates the degree of protrusion, and the present invention has been completed.

  In the present invention, as shown in FIG. 3, in the coordinate system in which the joint angle is the horizontal axis and the joint torque is the vertical axis, the angle-torque characteristic graph 80 has a joint torque larger than the straight line 82 connecting both ends of the graph 80. The joint angle range 83 is referred to as an “excessive joint torque range”. As shown in FIG. 2, when the angle-torque characteristic graph 70 does not substantially protrude above the straight line 72 connecting both ends of the graph 70, the “excessive joint torque range” is not defined.

  In the present invention, as an index indicating the degree to which the angle-torque characteristic graph 80 protrudes upward from the straight line 82, (1) the region surrounded by the angle-torque characteristic graph 80 in the excessive joint torque region 83 and the straight line 82 is used. The area A and (2) the maximum distance D between the angle-torque characteristic graph 80 and the straight line 82 in the excessive joint torque region 83 are used. The distance between the graph 80 and the straight line 82 is defined along a direction orthogonal to the straight line 82.

  The area A increases as the graph 80 greatly protrudes upward with respect to the straight line 82 and as the excessive joint torque region 83 increases. Since the area A correlates with the area (that is, impulse) of the region surrounded by the graph 80 and the horizontal axis in the excessive joint torque region 83, the resistance felt when the examiner 2 bends or extends the elbow joint of the subject 1 Can be used as an index for quantitatively expressing.

  In addition, the maximum distance D increases as the graph 80 greatly protrudes upward with respect to the straight line 82. Since the maximum distance D also correlates with the area (ie, impulse) of the region surrounded by the graph 80 and the horizontal axis in the excessive joint torque region 83, the resistance that the examiner 2 feels when bending or extending the elbow joint of the subject 1 It can be used as an index for quantitatively expressing feeling.

  By comparing the area A and the maximum distance D with respective reference values (threshold values), it is possible to objectively evaluate the presence or absence of spasticity.

  The calculation unit 50 calculates the area A and the maximum distance D. Further, the calculation unit 50 may compare the calculated area A and maximum distance D with respective reference values. The area A and the maximum distance D can be displayed on the output device 52. Moreover, the objective evaluation result of the presence or absence of spasticity obtained by comparing with the reference value can be displayed together with the output device 52.

  Both the area A and the maximum distance D are effective for objectively evaluating the presence or absence of spasticity. Therefore, it is sufficient for the calculation unit 50 to calculate only one of these. However, the calculation unit 50 may calculate both of them. Thereby, the evaluation accuracy of the presence or absence of spasticity is improved.

  As can be understood from the actual measurement graphs 70 and 80 showing the angle-torque characteristics of FIGS. 2 and 3, the actual measurement data of the change in the joint torque with respect to the joint angle includes a high-frequency vibration component (noise). Therefore, as the angle-torque characteristic graph for calculating the area A and the maximum distance D, instead of the actual measurement graphs 70 and 80 based on the actual measurement data, cubic function approximation graphs 71 and 81 obtained by approximating these with a cubic function are used. Also good. This is advantageous in improving the evaluation accuracy by eliminating the influence of noise and reducing the burden on the calculation unit 50 when calculating the area A and the maximum distance D.

  FIG. 4 shows an example of the change in joint torque with respect to the joint angle in the dynamic extension phase of the elbow joint, which is not recognized as spasticity on the healthy side (the side without paralysis) of the stroke patient, as in FIG. FIG. A solid line 90 is an actual measurement graph showing actual measurement data of a change in joint torque with respect to the joint angle. A broken line 91 is a cubic function approximation graph obtained by approximating the solid line 90 with a cubic function. An alternate long and short dash line 92 is a straight line connecting both ends of the solid line 90 (that is, the maximum extended position 90e and the maximum bent position 90f). Arrows indicate changes in time.

  As is apparent from a comparison of FIG. 4 with FIG. 2, the graph 90 has a convex curve shape in the initial stage of the process of extending the elbow joint from the maximum bending position 90f to the maximum extension position 90e when viewed macroscopically. It has a convex curve shape on the upper side at the end after that. The macroscopic shape of the graph 90 approximates that of the graph 80 shown in FIG. However, in the graph 90 of FIG. 4, almost no portion protruding above the straight line 92 can be recognized. Therefore, in FIG. 4, the excessive joint torque region (see the excessive joint torque region 83 of FIG. 3) is not substantially recognized.

  When the doctor examines such a patient, no apparent spasticity is recognized, so the MAS is determined to be zero. However, it is known that when motor paralysis appears in a stroke, most of the nerves descending from the cortical motor area cross the opposite side, but about 10% descend on the same side. Therefore, even on the healthy side of a stroke patient, some muscular tonus abnormality may appear due to a cortical lesion on the same side. The preferred embodiment of the present invention provides an indicator that can objectively distinguish between FIG. 2 and FIG. This will be described below.

  As shown in FIG. 4, the joint angle of the end having the small joint angle (maximum extended position 90e) among the both ends of the angle-torque characteristic graph 90 is the minimum joint angle θmin, and the end having the large joint angle (maximum bent position 90f). Is the maximum joint angle θmax. The difference between the minimum joint angle θmin and the maximum joint angle θmax is defined as a bendable / extendable range θef (θef = θmax−θmin). A joint angle larger than the minimum joint angle θmin by 10% of the bendable / extendable range θef is defined as a first joint angle θ1 (θ1 = θmin + θef * 0.1). A joint angle smaller than the maximum joint angle θmax by 10% of the bendable range θef is defined as a second joint angle θ2 (θ2 = θmax−θef * 0.1). A point on the straight line 92 having the first joint angle θ1 is defined as a first point P1, and a point on the straight line 92 having the second joint angle θ2 is defined as a second point P2. A distance between the first point P1 and the graph 90 is a first distance D1, and a distance between the second point P2 and the graph 90 is a second distance D2. The distances D1 and D2 are defined along a direction orthogonal to the straight line 92. The signs (positive / negative) of the distances D1 and D2 are “positive” when the graph 90 is located on the upper side of the points P1 and P2, and “negative” when the graph 90 is located on the lower side. Therefore, when the second distance D2 is defined below the straight line 92 as in the graph 90 of FIG. 4, the second distance D2 takes a negative value.

  In the preferred embodiment, the distances D1 and D2 defined as described above are used as indices for objectively distinguishing between FIG. 2 and FIG. For example, the first distance D1 and the second distance D2 can be compared with a reference value (threshold value). Here, a negative value can be set as the reference value. By setting an appropriate reference value, the first distance D1 and the second distance D2 defined in the same manner as the upper level with respect to the angle-torque characteristic graph 70 shown in FIG. 2 are both smaller than the reference value. Determined. On the other hand, for the first distance D1 and the second distance D2 defined with respect to the angle-torque characteristic graph 90 shown in FIG. 4, the first distance D1 is larger than the reference value, and the second distance D2 is It is determined that the value is smaller than the reference value.

  In this way, by comparing the first distance D1 and the second distance D2 of the two angle-torque characteristic graphs 70, 90 with the reference value, the difference in the curve shape of the angle-torque characteristic graphs 70, 90 is identified. can do. When one of the first distance D1 and the second distance D2 is larger than the reference value and the other is smaller than the reference value, it can be determined that the spasticity is present (MAS is 1).

  The calculation unit 50 calculates the distances D1 and D2. Further, the calculation unit 50 may compare the calculated distances D1 and D2 with a preset reference value. The distances D1 and D2 can be displayed on the output device 52. In addition, the result obtained by comparing the distances D1 and D2 with the reference value can be displayed together on the output device 52.

  Instead of the actual measurement graph 90 based on the actual measurement data, a cubic function approximation graph 91 obtained by approximating this with a cubic function may be used as the angle-torque characteristic graph for calculating the distances D1 and D2. This is advantageous in improving the evaluation accuracy by eliminating the influence of noise and reducing the burden on the calculation unit 50 when calculating the distances D1 and D2.

  Furthermore, the fact that the cubic function approximation graph 91 obtained by approximating the actual measurement graph 90 with a cubic function has an inflection point between the maximum extension position 90e and the maximum bending position 90f objectively distinguishes between FIG. 4 and FIG. Can be an indicator of The calculation unit 50 calculates the position of the inflection point of the cubic function approximation graph.

  As described above, in cases where it is determined that there is no spasticity on examination (MAS is 0), a case of a healthy person as shown in FIG. 2 and a case where there is a slight spasticity in muscle tonus as shown in FIG. And are included. By using the distances D1 and D2 provided by the muscle tonus measuring apparatus as evaluation indexes, it is possible to evaluate an abnormality of muscle tonus that cannot be detected by a doctor's examination. This is useful for objectively judging the prognosis of the disease and the effects of treatment and rehabilitation.

  As described above, the muscle tonus measuring apparatus of the present invention analyzes the angle-torque characteristic graph obtained by measuring the joint torque and the joint angle, and feels resistance when flexing or extending the joint passively. Quantify changes in This can be an index for objectively determining whether there is no spasticity (MAS is 0) or spasticity (MAS is 1 or more). In addition, the measurement of joint torque and joint angle can be performed in a diagnostic procedure that has been conventionally performed by doctors to determine the presence or absence of spasticity. Therefore, according to the present invention, efficiency and cost reduction of clinical trials can be realized. By displaying the angle-torque characteristic graph on the output device 52, the degree of spasticity can be visualized. This is very useful, for example, for doctors explaining the effects of treatment and rehabilitation to patients. Since the movement of flexing and extending the joints can be easily performed without being a doctor, for example, a family member can change the degree of spasticity of a patient at home by using the muscle tonus measuring device of the present invention. It is also possible to measure automatically.

  The present invention is not limited to the above embodiment and the following examples, and various modifications can be made.

  In the above embodiment, the angle-torque characteristic graph in the dynamic extension phase is used, but the angle-torque characteristic graph in the dynamic flexion phase can also be used. The jackknife phenomenon, which is a characteristic phenomenon of spasticity, may be observed only in one of the dynamic extension phase and the dynamic flexion phase, or in both cases. Therefore, the above-described indices (area A, maximum distance D, distances D1, D2) for objectively evaluating spasticity need to be calculated for at least one of the dynamic extension phase and the dynamic flexion phase. is there. Calculation for both of these is preferable from the viewpoint of more accurately evaluating spasticity.

  The change in resistance in the jackknife phenomenon occurs when the angle-torque characteristic graph has a convex curve shape (convex portion) on the upper side and a concave curved shape (concave portion) on the upper side. The angle-torque characteristic graph shown in the above embodiment has the convex part on the maximum extension position side and the concave part on the maximum bending position side. On the rear side, a recess may be provided on the maximum extension side. In this case as well, an index for objectively evaluating spasticity can be obtained in the same manner as described above. Therefore, the present invention can objectively evaluate spasticity regardless of the position of the convex part and the concave part in the angle-torque characteristic graph.

  2 to 4, the angle-torque characteristic graph is created in the coordinate system with the bending angle with respect to the state where the elbow joint is extended as the horizontal axis, but the angle is expressed in the coordinate system with the angle between the upper arm and the forearm as the horizontal axis. -A torque characteristic graph can also be created. Even in this case, the area A, the maximum distance D, and the distances D1 and D2 are calculated in the same manner as in the above embodiment, and the presence or absence of spasticity and its objective level Can be used for evaluation.

  The shape of the base on which the force sensors 20a and 20b and the gyro sensor 30 are mounted need not be substantially U-shaped or substantially U-shaped as in the above-described embodiment. For example, the overall shape is circular or elliptical. Or various polygons including a quadrangle, etc., and an annular body penetrating through the center may be used. Furthermore, the base may have a movable part, or a part or the whole of the base may have flexibility for the purpose of improving the wearability to the subject.

  Instead of the pair of force sensors 20a and 20b, a single force sensor that detects a pushing / pulling force applied when the examiner 2 flexes and extends the elbow joint of the subject 1 may be used.

  Further, a stage for mounting the joint of the subject may be provided, and a distance sensor that automatically measures the distance between the stage and the detection unit 10 may be further provided. Thereby, the rotation radius of the detection part 10 required when calculating a joint torque can be measured easily.

  In the above embodiment, the gyro sensor 30 for measuring the joint angle is mounted on the base 11 together with the force sensors 20a and 20b. Thereby, the whole apparatus can be reduced in size, and joint torque and joint angle can be measured simultaneously only by mounting | wearing a test subject with the detection part 10. FIG. However, in the present invention, the joint angle measurement method is not limited to this, and a known angle change measurement method can be used. For example, apart from the detection unit 10 including the force sensors 20a and 20b, a sensor (for example, a potentiometer or a rotary encoder) that performs angle measurement may be mounted near the joint of the subject via a jig. A flexion / extension motion may be photographed, and the joint angle may be measured via image recognition.

  A calculation unit that performs a predetermined calculation using the measured data and a display device that displays the calculation result may be downsized and mounted on the detection unit 10.

  The calculation unit 50 may be connected to another calculation processing device (server) via various networks (for example, the Internet). In this case, a part or all of the arithmetic processing performed by the arithmetic unit described in the above embodiment can be performed by the arithmetic processing device on the cloud. In addition, various data measured by the detection unit 10 can be stored in an arithmetic processing device on the cloud. Or the calculating part 50 may be arrange | positioned on a cloud and the detection part 10 and the calculating part 50 may be connected via various networks (for example, the internet). As described above, by arranging a part or all of the arithmetic unit on the cloud, it is possible to realize a portable torso measuring device terminal having a detection unit, a connection function with a network, and a display unit. it can.

  Of course, the measuring device of the present invention can be applied to joints other than the elbow joint (for example, wrist and knee joints). The shape of the detection unit 10 can be appropriately changed according to the joint to be applied. In this case, the reference value (threshold value) for evaluating the above various indexes obtained from the angle-torque characteristic graph is appropriately set according to the joint.

  The muscle tonus measuring device of the present invention can be integrated with the muscle tonus measuring device of Patent Document 1 or Patent Document 2.

  The degree of spasticity of the subject's elbow joint was evaluated by a skilled physician based on the MAS shown in Table 1. The subject's elbow spasticity was 0 to 3 in MAS.

  Subsequently, the joint angle and joint torque of the elbow joint were measured using the muscle tonus measuring apparatus shown in FIG.

  The subject is relaxed in a resting position, and the examiner 2 supports the elbow joint of the subject 1 with one hand and the subject 1 with the wrist joint through the detection unit 10 with the other hand. A flexion and extension movement of elbow joint No. 1 was performed. The measurement starts from the maximum extension position, stops for 3 seconds or more at the maximum extension position, bends over 1 second, stops for 3 seconds or more at the maximum bending position, extends for 1 second, stops for 3 seconds or more at the maximum extension position, and so on. The flexion and extension movement was repeated for about 60 seconds. 5 flexion and extension movements per trial are included.

  For each of the dynamic flexion phase and the dynamic extension phase, using the measured data of the joint angle and joint torque, the joint torque with respect to the joint angle in the coordinate system with the joint angle as the horizontal axis and the joint torque as the vertical axis An angle-torque characteristic graph (measurement graph) showing a change in the angle was prepared. Regarding the joint torque, the torque due to gravity was corrected. Further, a cubic function approximation graph was created by approximating the angle-torque characteristic graph with a cubic function in the coordinate system. It was determined whether or not the cubic function approximate graph has a portion (excessive joint torque range) having a joint torque larger than a straight line connecting both ends of the cubic function approximate graph. In the case of having the excessive joint torque region 83 (see FIG. 3), the area A of the region surrounded by the cubic function approximation graph 81 and the straight line 82 in the excessive joint torque region 83 and the excessive joint torque region 83 The maximum distance D between the cubic function approximation graph 81 and the straight line 82 was calculated. In the coordinate system, the area A and the maximum distance D were calculated by setting 1 radian of the joint angle on the horizontal axis as “1” and 1 N · m of the joint torque on the vertical axis as “1”.

  For 49 elbow joints, spasticity was evaluated by a doctor, and area A and maximum distance D were calculated by a muscle tonus measuring device. In all of the dynamic flexion phase and the dynamic extension phase, the case where the area A was 0.3 or less (including the case where the excessive joint torque region was not included) was determined as “negative”, and the other cases were determined as “positive”. Also, when the maximum distance D is 0.2 or less in all of the dynamic flexion phase and the dynamic extension phase (including the case where there is no excessive joint torque range), it is judged as “negative”, and other cases are judged as “positive” did.

  Table 2 shows the evaluation results of the presence or absence of spasticity by the doctor and the evaluation results using the area A.

  Table 3 shows the evaluation results of the presence or absence of spasticity by the doctor and the evaluation results using the maximum distance D.

  From Tables 2 and 3, it was confirmed that the area A and the maximum distance D can be an accurate index for objectively determining the presence or absence of spasticity.

  By using the muscle tonus measuring apparatus of the present invention, the presence or absence of spasticity can be easily determined objectively. Therefore, the present invention can be widely used for, for example, determining the presence or absence of spasticity, determining the effects of medication or rehabilitation, and the like.

1 Test subject 10 Detection unit 50 Calculation units 70, 80, 90 Angle-torque characteristic graph (actual measurement graph)
71, 81, 91 Angle-torque characteristic graph (cubic function approximation graph)
72, 82, 92 Straight line 83 Excessive joint torque range A Area D Maximum distance θe Maximum extension position angle θf Maximum bending position angle θef Bendable extension range θ1 First joint angle θ2 Second joint angle D1 First distance D2 Second distance

Claims (5)

A muscle tonus comprising: a detection unit that detects a joint torque and a joint angle of the joint when the joint of the subject is dynamically flexed and extended; and a calculation unit that calculates a signal from the detection unit A measuring device,
In a coordinate system in which the joint angle is the horizontal axis and the joint torque is the vertical axis, the angle-torque characteristic graph showing the change of the joint torque with respect to the joint angle is larger than the straight line connecting both ends of the angle-torque characteristic graph. When the range of joint angles with joint torque is the excessive joint torque range,
The calculation unit includes an area of a region surrounded by the angle-torque characteristic graph and the straight line in the excessive joint torque region, and an angle-torque characteristic graph and the straight line in the excessive joint torque region. A muscle tonus measuring apparatus, wherein at least one of the maximum distances is calculated for at least one of a dynamic flexion phase and a dynamic extension phase.   The muscle tonus measuring apparatus according to claim 1, wherein the calculation unit calculates at least one of the area and the maximum distance for both a dynamic flexion phase and a dynamic extension phase. In the coordinate system, a joint angle of an end having a small joint angle among both ends of the angle-torque characteristic graph is a minimum joint angle, a joint angle of an end having a large joint angle is a maximum joint angle, and the minimum joint angle and the The difference from the maximum joint angle is defined as a bendable / extendable range, the joint angle larger than the minimum joint angle by 10% of the bendable / extendable range is defined as the first joint angle, and the joint is smaller than the maximum joint angle by 10% of the bendable / extendable range. When the angle is the second joint angle,
The calculation unit includes a first distance between the first point on the straight line having the first joint angle and the angle-torque characteristic graph, a second point on the straight line having the second joint angle, and the The muscle tonus measuring device according to claim 1 or 2, wherein the second distance from the angle-torque characteristic graph is calculated for at least one of the dynamic flexion phase and the dynamic extension phase.   The muscle tonus measuring apparatus according to claim 3, wherein the calculation unit calculates the first distance and the second distance for both a dynamic flexion phase and a dynamic extension phase.   The muscle tonus measuring apparatus according to any one of claims 1 to 4, wherein the calculation unit obtains the angle-torque characteristic graph by approximating a change in the joint torque with respect to the joint angle by a cubic function.

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