JP5836429B2 - Body state presentation apparatus, method and program - Google Patents

Description

  The present invention relates to a technique for presenting physical information.

  It is extremely important that an actor objectively grasps his / her physical movements in order to appropriately acquire basic movements of sports such as pitching in baseball, swinging in batting, golf, and putting. It is an improvement of the behavior that the actor performs while looking at himself in the mirror, or the behavior of the actor is recorded on the video and the actor himself observes it to find the problem of the behavior. This is an effective approach. However, the information obtained by observing the body movement is only the mechanical movement state of the body part, and the activity state of the muscle that produces the movement cannot be directly grasped.

  On the other hand, there is a technique for acquiring an activity state of a muscle from an electromyogram signal and presenting the information superimposed on an image of a body part (for example, see Non-Patent Document 1). However, performing an operation while watching a video may significantly hinder the task.

  On the other hand, it is easy to perform body movements while listening to acoustic signals, and auditory information is suitable for simultaneous acquisition while performing body movements compared to visual information. If it is possible to grasp the state of muscle strength in real time during task execution using auditory information, it will be easier to check the timing and strength of the actor himself, and facilitate the discovery of problems in body movement Is done. For this reason, a technique has been proposed in which changes in the activity state of muscles are reflected in changes in the characteristics of acoustic signals and presented to an actor in real time as auditory information (see, for example, Non-Patent Document 2).

Naoto Igarashi, Kengo Suzuki, Hiroaki Kawamoto, Yoshiyuki Sankai, “Wearing Light-Emitting Sensor Suit Presenting Lower Limb Movement State”, Information Processing Society of Japan Interaction 2011 Masaki Matsubara, Yoko Terasawa, Hideki Kadone, Kengo Suzuki, Shoji Makino, “Muscle Activity Awareness for Understanding the Linkage of Body Movements”, Proceedings of the Autumn Meeting of the Acoustical Society of Japan, P.919-922, 2012

  By the way, the muscle activity state does not always correspond to the mechanical motion state of the body part on which the muscle acts, for example, even when the arm is stationary, the muscle that moves the arm exerts a large force. In some cases. Such a situation occurs when a plurality of muscles in an antagonistic relationship exert their power and balance each other. When antagonistic muscles exert excessive force when complex and quick body movements must be performed continuously, a so-called “strengthening” state occurs, which acts as a factor that hinders the realization of smooth movement. To acquire a task with high difficulty, it is necessary to simultaneously reduce such a force state as much as possible and to exert muscular strength with appropriate timing and strength. In such a case, for example, as in the prior art described in Non-Patent Document 2, the muscular strength is accurately exerted even in the force state only by directly reflecting the change in the electromyogram signal in the change in the acoustic signal. Even in such a state, a change in the acoustic signal occurs in the same manner, and there may be a problem that the two cannot be distinguished from each other.

  An object of the present invention is to provide an apparatus, a method, and a program for presenting body condition that present useful information about the body condition than before.

The physical condition presentation device according to one aspect of the present invention represents a muscle signal generation unit that generates a muscle signal, which is a signal representing an activity level of a muscle to be measured, and a kinematic state of a body part on which the muscle acts. An acceleration signal generation unit that generates an acceleration signal that is a signal, and a modulation unit that modulates a predetermined wave signal based on the relationship between the muscle signal and the acceleration signal and presents the modulated wave signal .

  More useful information about the physical condition than before can be presented.

The block diagram for demonstrating the example of a physical condition presentation apparatus. The flowchart for demonstrating the example of the body state presentation method. The figure which shows the example of the mounting | wearing site | part of the electromyogram electrode A and the acceleration sensor B. FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the physical information presentation device includes an electromyogram signal storage unit 1, a muscle signal generation unit 2, a muscle signal storage unit 3, an acceleration electrical signal storage unit 4, an acceleration signal generation unit 5, and an acceleration signal storage unit. 6. A modulation unit 10 is provided, for example. The modulation unit 10 includes, for example, a modulation signal generation unit 7 and a wave vibration modulation unit 8. The physical condition presentation method is realized by the physical information presentation device performing the processing from step S1 to step S5 in FIG.

  It is assumed that the electromyographic electrode A is attached to a muscle that plays a major role in the body motion in a desired exercise task, and the acceleration sensor B is attached to a body part on which the muscle acts. In FIG. 1, an electromyographic electrode A is attached to the upper arm, and an acceleration sensor B is attached to the hand.

  FIG. 3 shows an example of an attachment site of the electromyogram electrode A and the acceleration sensor B suitable for each task for some basic exercise tasks. When the exercise task is hand bending, the electromyographic electrode A is attached to the carpal flexor and the acceleration sensor B is attached to the back of the hand. When the exercise task is hand extension, the electromyogram electrode A is attached to the carpal extensor and the acceleration sensor B is attached to the back of the hand. When the exercise task is prorotation of the forearm, the electromyographic electrode A is attached to the supination muscle, and the acceleration sensor B is attached to the back of the hand or the wrist. When the exercise task is pronation of the forearm, the electromyographic electrode A is attached to the pronation muscle, and the acceleration sensor B is attached to the back of the hand or the wrist. When the exercise task is plantar flexion, the electromyographic electrode A is attached to the gastrocnemius or soleus, and the acceleration sensor B is attached to the instep. When the exercise task is dorsiflexion of the foot, the electromyographic electrode A is attached to the anterior tibial muscle and attached to the instep of the foot.

An electromyogram signal x _A (t), which is an electrical signal acquired from the electromyogram electrode A, is sampled at a predetermined sampling period T and stored in the electromyogram signal storage unit 1. The electromyographic signal storage unit 1, the sample values of the latest N _A number of EMG signals are stored. _A sample value series of the latest N _A EMG signals is expressed as x _A ^m (n) (0 ≦ n <N _A ). Each time a new M sample values are generated from the electromyogram signal x _A (t), for example, the latest N _A EMG signal sample value series x _A ^m (n) (0 ≦ n <N _A ) is updated. However, M <NA.

The muscle signal generator 2 generates a muscle signal p _A ^m that is a signal representing the activity level of the muscle to be measured (step S1). The generated muscle signal is stored in the muscle signal storage unit 3.

Muscle signal generator 2, for example, every time the sample value of the M new EMG signal is obtained, the sample value series of the latest N _A number of electromyographic signals read from EMG signal storage unit 1 The amplitude of the electromyogram signal is calculated using x _A ^m (n) (0 ≦ n <N _A ). The amplitude of the EMG signal is an example of a streak signal p _A ^m is a signal representative of the activity level of the subject to muscular measurement. Therefore, also referred to as p _A ^m the amplitude of the EMG signal.

The amplitude p _A ^m of the electromyogram signal may be an average absolute amplitude that is an average of the absolute values of the electromyogram signal defined by the equation (1), or a muscle defined by the equation (2). It may be a maximum absolute amplitude that is the maximum absolute value of the electrogram signal, or a mean square amplitude that is a geometric mean of the electromyogram signal defined by the equation (3).

The muscle signal storage unit 3 stores the latest M _A muscle signals p _A ^m . The latest M _A muscle signals stored in the muscle signal storage unit 3 are expressed as p _A (m) (0 ≦ m <M _A ). New every muscle signal p _A ^m is produced, for example, the latest M _A number of muscle signal p _A (m) as follows (0 ≦ m <M _A) is updated.

The acceleration electrical signal x _B (t), which is an electrical signal acquired from the acceleration sensor B, is sampled at a predetermined sampling period T and stored in the acceleration electrical signal storage unit 4. The acceleration electric signal storage unit 4, sample values of the latest N _B number of the acceleration electric signal is stored. The sample value sequence of the latest N _B number of the acceleration electric signal is denoted as ^{_{x B m (n) (0}} ≦ n <N B). Each time a new M-number of sampled values from EMG signal x _B (t) is generated, the sample value sequence x for example, the following recent N _B number of EMG signals as _B ^m (n) (0 ≦ n <N _B ) is updated. However, M <NB.

  The acceleration signal generation unit 5 generates an acceleration signal that is a signal representing the kinematic state of the body part on which the muscle to be measured acts (step S2). The generated acceleration signal is stored in the acceleration signal storage unit 6.

Acceleration signal generator 5, for example, every time the sample value of the M new acceleration electric signal is obtained, the sample value series of the latest N _B number of acceleration electric signal read from the acceleration electric signal storage unit 4 x _B ^m (n) The amplitude of the acceleration signal is calculated using (0 ≦ n <N _B ). The amplitude of the acceleration signal is an example of an acceleration signal p _B ^m that is a signal representing the kinematic state of the body part on which the muscle to be measured acts. Therefore, the amplitude of the acceleration signal is also expressed as p _B ^m .

The amplitude p _B ^m of the acceleration signal may be an average absolute amplitude that is an average of absolute values of the acceleration electrical signal defined by the equation (4), or may be an acceleration electrical signal defined by the equation (5). It may be the maximum absolute amplitude that is the maximum absolute value, or the mean square amplitude that is the geometric mean of the acceleration electrical signal defined by Equation (6).

The muscle signal storage unit 3 stores the latest M _B muscle signals p _B. The latest M _B muscle signals stored in the muscle signal storage unit 3 are expressed as p _B (m) (0 ≦ m <M _B ). Each time a new muscle signal p _B ^m is generated, for example, the latest M _B muscle signals p _B (m) (0 ≦ m <M _B ) are updated as follows.

  The modulation unit 10 modulates a predetermined wave signal based on the relationship between the muscle signal and the acceleration signal (step S5). The process of the modulation unit 10 is realized by the process of step S3 by the modulation signal generation unit 7 and the process of step S4 by the wave signal modulation unit 8. Hereinafter, these processes will be described.

  The modulation signal generation unit 7 generates a modulation signal obtained by modulating the muscle signal with the acceleration signal (step S3). The generated modulation signal is output to the wave signal modulation unit 8.

For example, the modulation signal generation unit 7 includes the latest M _A muscle signals p _A (m) (0 ≦ m <M _A ) read from the muscle signal storage unit 3 and the latest M read from the acceleration signal storage unit 6. _{Using B} acceleration signals p _B (m) (0 ≦ m <M _B ), a modulation signal p _C ^m defined by the following equation is generated. M _A and M _B are integers of 1 or more. M _A and M _B may be particularly 1. p _A (m) ^rep is a representative value of the muscle signal p _A (m) (0 ≦ m <M _A ), and p _B (m) ^rep is the acceleration signal p _B (m) (0 ≦ m <M _B ) Is a representative value.

In the equation above, although the p _A (m) ^rep is the arithmetic mean of M _A number of muscle signal _{p A (m) (0 ≦} m <M A), p A (m) rep is M _A number of muscle Other values may be used as long as they represent the signal p _A (m) (0 ≦ m <M _A ). For example, p _A (m) ^rep is, M _A number of muscle signal _{p A (m) (0 ≦} m <M A) may be a geometric mean of, M _A number of muscle signal p _A (m) It may be the maximum value (0 ≦ m <M _A ).

Similarly, in the above formula, although the p _B (m) ^rep is the arithmetic mean of M _B-number of the acceleration signal _{p B (m) (0 ≦} m <M B), p B (m) rep is M _B Other values may be used as long as they represent values of the acceleration signals p _B (m) (0 ≦ m <M _B ). For example, p _B (m) ^rep is, M _B-number of the acceleration signal _{p B (m) (0 ≦} m <M B) may be a geometric mean of, M _B-number of the acceleration signal p _B (m) It may be the maximum value of (0 ≦ m <M _B ).

The function _{f, (1) p A (m} ) rep, may be a function f ₁ is a monotonically non-decreasing for each ^{_{p B (m) rep, (}} 2) p A (m) rep Monotone non It may be a function f ₂ that is decreasing but monotonically non-increasing for p _B (m) ^rep . The case of (1) is called method (1), and the case of (2) is called method (2). The merits of the method (1) and the method (2) will be described later. Examples of the functions f ₁ and f ₂ are given below.

Note that when the function f ₂ exemplified above is used as the function f, p _C ^m = 0 when p _B (m) ^rep = 0. As a result, it is possible to avoid the problem that the value of p _C ^m is not determined due to the denominator becoming zero.

  As described above, the modulation signal generation unit 7 generates the modulation signal by calculating the output value when the representative value of the muscle signal and the representative value of the acceleration signal are input to the predetermined function f, for example.

The wave signal modulation unit 8 modulates a predetermined wave signal based on the modulation signal p _C ^m (step S4). The modulated wave signal is presented to the actor and observer. The wave signal modulator 8 may be a sound source signal modulator that modulates a predetermined sound source signal g (t), or may be an optical signal modulator that modulates a predetermined optical signal.

When the wave signal modulation unit 8 is a sound source signal modulation unit, the wave signal modulation unit 8 performs, for example, amplitude modulation or frequency modulation on the sound source signal g (t) on the basis of the modulation signal p _C ^m to generate the acoustic signal s. Generate (t).

  Amplitude modulation is performed by the following equation, for example. D is a predetermined gain for determining the degree of the modulation effect. When amplitude modulation is performed, the sound source signal g (t) may be any signal.

On the other hand, frequency modulation is performed by the following formula, for example. G _k means the amplitude of the k-th harmonic. D is a predetermined gain for determining the degree of the modulation effect.

  In the case of performing frequency modulation, the sound source signal g (t) is a composite sine wave having a predetermined fundamental frequency f and an integer multiple thereof defined by the following equation, for example.

When the wave signal modulation unit 8 is an optical signal modulation unit, the wave signal modulation unit 8 performs amplitude modulation or frequency modulation on a predetermined optical signal based on the modulation signal p _C ^m .

When amplitude modulation is performed, the wave signal modulation unit 8 modulates the luminance of an optical signal having a predetermined luminance based on the modulation signal p _C ^m . Thereby, the brightness of the light displayed on the LED or the display can be changed.

  When frequency modulation is performed, the wave signal modulation unit 8 modulates the frequency of an optical signal having a predetermined frequency based on the modulation signal. Thereby, the color of the light displayed on the LED or the display can be changed.

  In the case where the wave signal modulation unit 8 is a sound source signal modulation unit, when the method (1) is used, the acoustic signal changes and exercises only in a time interval in which the movement of the body part changes with the exertion of muscle strength. The state of muscular strength without change is not reflected in the change of the acoustic signal. Therefore, the method (1) is effective for grasping at what timing and with which strength the muscle activity directly related to the unit movement most important in the task has occurred.

  On the other hand, when the wave signal modulation unit 8 is a sound source signal modulation unit and the method (2) is used, in the method 2, the muscular strength exerted state without the motion change is reflected in the acoustic signal change, and the motion changes. The acoustic signal does not change during the time interval. Therefore, the method (2) is effective in grasping whether or not an excessive “force” state is generated in a task that should perform a smooth continuous motion with a minimum muscle activity.

  Moreover, the wave signal modulation | alteration part 8 may show a body information to an actor and an observer as visual information. In this case, the wave signal modulation unit 8 changes the visual information that reflects only the muscle activity directly related to the important motion in the exercise task (when the method (1) is used) and unnecessary force in the exercise task. Any of visual information changes reflecting only the state (when using method (2)) may be selectively presented to the actor or the observer.

  When the muscle activity level is directly reflected in the visual information, the presentation information changes even when the muscle is in an unnecessary force state during a series of physical movements and when the muscle strength is accurately demonstrated. Therefore, as the movement becomes faster and more complicated, the variation in the visual information presented increases, and it may become difficult to grasp how much each muscle has acted at what timing. This difficulty can be avoided by selectively presenting visual information as described above.

  In order to master tasks that are particularly difficult, it is required to reduce the excessive force state as much as possible and to exert muscular strength with appropriate timing and strength at the same time. By using such a body state presentation apparatus and method, the muscular strength exerted state in the body motion in the desired task can be accurately grasped in real time while the actor himself performs the task.

[Variations]
There is a time delay (electrodynamic delay) of less than about 100 milliseconds between the start time of the muscle activity observed by the electromyogram and the start time of the mechanical movement of the body part due to the activity. . Therefore, a time lag corresponding to this electrodynamic delay is included between the muscle signal p _A (m) and the acceleration signal p _B (m). Therefore, p _C ^m may be calculated by shifting one of p _A (m) ^rep and acceleration signal p _A (m) ^rep by the time corresponding to the electrodynamic delay.

For example, the p _A (m) ^rep that delayed by the amount of time corresponding to the electrodynamic delay as ^{_{p A (m) rep + Δ}} , calculates the modulated signal p _C ^m which is defined by the following equation. Specifically, p _A (m) ^{rep + Δ} is p _A (m) ^{rep at} a time delayed by a discrete time Δ ′ / MT from the time of p _A (m) ^rep , where Δ ′ is the electrodynamic delay. That is.

Also, even if the modulation signal p _C ^m defined by the following equation is calculated with p _B (m) ^rep advanced by the time corresponding to the electro-mechanical delay as p _B (m) ^rep-Δ , Good. Specifically, p _B (m) ^rep-Δ is expressed as p _B (m) ^rep at a time that is advanced by a discrete time Δ ′ / MT from the time of p _B (m) ^rep , where Δ ′ is the electrodynamic delay. That is.

  In the above embodiment, when the wave signal modulation unit 8 is a sound source signal modulation unit, one type of sound source is controlled using signals from one electromyogram electrode and one acceleration sensor. On the other hand, when there are muscles that are important for a desired task in multiple parts, one electrode is attached to each of those muscles, and one acceleration sensor is attached to the body part where each muscle acts. One sound source controlled by each muscle signal and acceleration signal may be assigned one by one. However, the individual sound sources are different types of sound sources that are audibly distinguishable from each other. Moreover, it is good also as a structure which shares an acceleration sensor regarding the muscle with which the body part which acts acts among several muscles.

  As a means for acquiring the kinematic state of the body part, in addition to using the acceleration sensor B, a gyro sensor, an inclinometer, a geomagnetometer, or the like can be used. Or, using a device such as a video camera that acquires video in real time and an image processing arithmetic device that estimates the spatial position of a specific part of the body from the acquired video, the displacement, speed, acceleration, etc. of the desired body part Information may be acquired.

  The physical condition presentation device may include a differential dispersion modulation signal generation unit 9 indicated by a broken line in FIG.

The differential dispersion modulation signal generation unit 9 is assumed to have time-series data of the modulation signal ^ p _C ^m to be compared, for example. The modulation signal ^ p _C ^m to be compared is generated in advance based on a model motion for a predetermined motion task. The differential dispersion modulation signal generation unit 9 calculates a difference Δp _C ^m between p _C ^m and ^ p _C ^m generated by the modulation signal generation unit 7, and outputs the calculated difference Δp _C ^m to the wave signal modulation unit 8. To do. The wave signal modulation unit 8 modulates a predetermined wave signal in the same manner as described above based on the difference Δp _C ^m . In this way, by presenting the physical state based on the difference Δp _C ^{m from the} modulation signal ^ p _C ^m to be compared, the actor can determine the difference between the exemplary movement and his movement, in other words, You can effectively perceive how close your exercise is to the exemplary exercise.

Further, difference variance modulation signal generating unit 9 may store the modulated signal p _C ^m modulated signal generator 7 is generated so far, the modulation signal p _C each time a new modulation signal p _C ^m is generated and calculating the variance .sigma.p _C ^m of ^m, may output the computed variances .sigma.p _C ^m wave signal modulator 8. The wave signal modulation unit 8 modulates a predetermined wave signal based on the dispersion σp _C ^m in the same manner as described above. In this way, by presenting the physical state based on the variance σp _C ^m , the actor effectively perceives how much his movement has been reproduced, in other words, the magnitude of his movement blur. can do.

  The processes described in the apparatus and method are not only executed in chronological order according to the order of description, but may be executed in parallel or individually according to the processing capability of the apparatus that executes the processes or as necessary.

  Further, when each process in each device is realized by a computer, the processing contents of the functions that each device should have are described by a program. Then, by executing this program on a computer, each process is realized on the computer.

  The program describing the processing contents can be recorded on a computer-readable recording medium. As the computer-readable recording medium, for example, any recording medium such as a magnetic recording device, an optical disk, a magneto-optical recording medium, and a semiconductor memory may be used.

  Each processing means may be configured by executing a predetermined program on a computer, or at least a part of these processing contents may be realized by hardware.

  Needless to say, other modifications are possible without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Electromyogram signal storage part 2 Muscle signal generation part 3 Muscle signal storage part 4 Acceleration electric signal storage part 5 Acceleration signal generation part 6 Acceleration signal storage part 7 Modulation signal generation part 8 Wave signal modulation part 9 Differential dispersion modulation signal generation part 10 Modulator

Claims (5)

A muscle signal generation unit that generates a muscle signal that is a signal representing an activity level of a muscle to be measured;
An acceleration signal generation unit that generates an acceleration signal that is a signal representing a kinematic state of a body part on which the muscle acts;
A modulation unit that modulates a predetermined wave signal based on the relationship between the muscle signal and the acceleration signal, and presents the modulated wave signal ;
A body condition presentation device including: The physical condition presentation device according to claim 1,
An electromyographic electrode attached to the muscle;
An acceleration sensor mounted on the body part,
The muscle signal is the amplitude of the electromyogram signal obtained from the electromyogram electrode attached to the muscle,
The acceleration signal is an amplitude of an acceleration signal obtained from an acceleration sensor attached to the body part.
Physical condition presentation device. The physical condition presentation device according to claim 1 or 2,
The modulation unit generates a modulation signal by calculating an output value when a representative value of the muscle signal and a representative value of the acceleration signal are input to a predetermined function f, and the modulation signal And a wave signal modulator that modulates the predetermined wave signal based on
The predetermined function f is a function f ₁ that is monotonically non-decreasing for each of the representative value of the muscle signal and the representative value of the acceleration signal, or is monotonous non-decreasing for the representative value of the muscle signal, A function f ₂ that is monotonically non-increasing with respect to the representative value,
Physical condition presentation device. A muscle signal generation step in which a muscle signal generation unit generates a muscle signal that is a signal representing an activity level of a muscle to be measured;
An acceleration signal generating unit that generates an acceleration signal that is a signal representing a kinematic state of a body part on which the muscle acts;
Modulation unit modulates the predetermined wave signals based on the relationship between the muscle signal and the acceleration signal, the answering step to present a modulated wave signal,
A physical condition presentation method including: The program for functioning a computer as said each part of the physical condition presentation apparatus in any one of Claim 1 to 3.

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