JP2773734B2 - Physical activity measurement system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a physical activity measurement system, and more particularly to a physical activity measurement system for biological measurement.

[0002]

2. Description of the Related Art Conventionally, a physical activity measuring system of this kind has been used in order to secure the amount of exercise necessary to obtain good sleep, as disclosed in Japanese Patent Application Laid-Open No. 5-285126, for example. It is used to measure the amount of activity. FIG. 8 is an overall schematic diagram showing an example of a conventional physical activity amount measurement system, and FIGS.
It is a perspective view which shows a structure of. In FIG. 8, the measuring unit 10
0 outputs the result of measuring the amount of physical activity at predetermined time intervals or continuously. The storage unit 101 stores the measurement value output from the measurement unit 100. The arithmetic unit 102 outputs the result of integrating all the measured values from the start of the measurement. The comparing unit 103 compares the amount of activity necessary for obtaining good sleep with the integrated value of the measured values. The display unit 104 is a comparison unit 103
And the difference is displayed when the integrated value is smaller than the amount of activity necessary to obtain good sleep. In this technology, only the measuring unit 100 is related to the physical activity amount measurement itself.

Next, the operation up to the measurement of the amount of physical activity will be described. As shown in FIGS. 9A and 9B, a ball 130 is sealed in a cylindrical container 120 made of a piezoelectric element.
On the person's wrist. If the electrodes are arranged in the container 120, the ball 130 collides with the container 120 with the movement of the arm, so that a voltage signal having an amplitude and a frequency corresponding to the amount of activity can be extracted. Based on this voltage signal, the amount of activity at every predetermined time or the amount of instantaneous activity can be measured.

[0004]

A first problem is that information on a posture that greatly contributes to the amount of physical activity is not available. The reason is that it is difficult to classify postures such as a standing position, a sitting position, and a supine position other than the periodic movement accompanied by the arm movement in the measurement of only the arm movement.

[0005] The second problem is that it is not possible to measure exercise involving weight shift, which significantly affects the amount of activity, that is, behavior involving leg movement. The reason is that not only the measurement of the movement of the arm but also the movement on the desk and the action such as walking cannot be distinguished, and the action involving the movement of the foot including the stair walking cannot be classified.

[0006]

The physical activity measuring system according to the present invention comprises a pressure sensor (1 in FIG. 1) which is mounted on a heel to measure a load, a ratio of a load to a subject's body weight and a load. It has a signal processing unit (3 in FIG. 1) that determines a posture and an action from a time-series change (load pattern) and outputs the result to the outside.

[0007] Since most of the physical activities, ie, postures and actions, involve movement of the center of gravity, the load and posture on the heel,
And there is a high correlation between the temporal change of the load and the behavior. For this reason, by using the load signal measured by the pressure sensor arranged on the heel, the signal processing unit determines the ratio of the load to the weight of the subject and the characteristics of the temporal change of the load to determine the posture and behavior. Can be classified, and the amount of physical activity can be measured.

Specifically, the signal processing unit according to the present invention comprises: means for calculating a parameter K which is a ratio of a load applied to the pressure sensor to a body weight of the subject;
Change detection means for detecting whether a temporal change occurs, generating a change detection signal when a temporal change is detected, and generating a no change detection signal when no temporal change occurs, When a no-change detection signal is generated, a standing position, a sitting position, and a supine position are determined from the parameter K from the arithmetic unit,
A first determining means for generating a determination result, and a second determining means for determining, based on a parameter K from the arithmetic means, walking, ascending or descending a stair, and generating a determination result when a change detection signal is generated. And Accordingly, the posture in the stationary state is determined by the first determination unit, and the moving state, that is, the exercise state when the load on the heel changes with time, is determined by the second determination unit.

The first determination means compares a threshold value with a parameter K with a threshold value generation circuit for generating a threshold value for determining a standing position, a sitting position, and a supine position.
The provision of the determination circuit for determining the standing position, the sitting position, and the supine position simplifies the circuit configuration and facilitates digitization.

The second determining means compares a threshold value with a peak value of the parameter K, and a threshold value generating circuit for generating a threshold value for discriminating between walking, going up stairs, and going down stairs. Therefore, the provision of the determination circuit for determining walking, ascending of stairs, and descending of stairs simplifies the circuit configuration and facilitates digitization.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing a physical activity measurement system according to a first embodiment of the present invention, and FIG.
Is an external view showing the method of use. In the figure, a pressure sensor 1 mounted on a heel is connected to a signal processing unit 3 mounted on an ankle via a signal line 2 to supply a pressure signal. The signal processing unit 3 performs signal processing based on the pressure signal, and outputs a result to the external device 7 via the signal line 6.

Next, the operation of the measurement system shown in FIG. 1 will be described. In FIG. 1, the load measured by the pressure sensor 1 is used to determine the posture and behavior of the person to be measured by the signal processing unit 3 using the following algorithm.

Assuming that the posture is classified into one of a standing position, a sitting position, and a supine position, a specific classification standard is shown in FIG.
To (C). When the parameter K is a ratio of the load F to the weight of the subject, the detection range of the parameter K in the standing position shown in FIG. 3A is preferably 50% to 100% (however, 100% is not included). This range is defined as 50% when the weight is equally distributed to the foot 4 on the measurement side and the foot 5 on the non-measurement side shown in FIG. 2 and 100% of standing on one leg or walking. . The load F is detected from the pressure sensor 1, the parameter K is calculated by the signal processing unit 3, and it is detected whether the load F is within the detection range of 50 to 100%.

In the locus shown in FIG. 3B, the detection range of the parameter K is preferably 0% to 50% (however, 0% and 50%).
% Is not included). In the sitting position, the foot 4 in FIG. 2 touches the ground and a little load is applied to the heel, so that 0% is not included. In the sitting position, since the weight is mainly supported by the seating surface, the load applied to the heel of the foot 4 in FIG. 2 is reduced. However, here, the weight is set to 50% for the sake of classification with the standing position. .

In the supine position shown in FIG.
Is preferably 0%. This is because it is considered that there is no load applied to the heel of the foot 4 in FIG. 2 in the sleeping state. By calculating the ratio of the load to the weight of the person to be measured based on the above criteria, the standing, sitting, and supine postures can be determined.

The signal processing unit 3 of the measurement system shown in FIG.
Then, the action of walking, climbing stairs, and descending stairs can be determined from the ratio of the load to the weight of the subject and the time-series change (load pattern) of the load. The specific classification criteria are shown in FIGS. 4A to 4C in which the pattern of the parameter K (the ratio of the load F to the weight of the subject) is shown in FIG.
(A) to (C).

In the walking shown in FIG.
Is preferably 0% to 100%. Since the weight is applied to the foot 5 in FIG. 2 and the load applied to the heel disappears when the foot 4 is separated, the weight is set to 0%. Conversely, when the foot 4 in FIG. 2 lands on the ground and the foot 5 leaves the ground,
100% in order to support it. As described above, the pattern of the parameter K during walking repeatedly changes periodically as shown in FIG. 5A in the set detection range.

When climbing the stairs as shown in FIG. 4B, the detection range of the parameter K is preferably 0% to 50%. When the foot 5 in FIG. 2 is landing on the stairs and the foot 4 is stepping up to go up the stairs, there is no load on the heel, so 0% is set. When the foot 4 lands on the stairs and the foot 5 leaves the stairs, the foot 4 will support the entire weight. here,
Since the weight when climbing the stairs is mainly supported around the toes, the load on the heel is reduced as compared with when walking, so the weight is set to 50% for convenience. The pattern of the parameter K repeats a periodic variation in the set detection range as shown in FIG.

When the vehicle descends the stairs as shown in FIG. 4C, the detection range of the parameter K is preferably 0% to 200%.
%. Since there is no load on the heel until the foot 4 in FIG. 2 separates from the stairs and lands on the next stairs, it is set to 0%.
When the foot 4 lands on the stairs, a load equal to or greater than the weight is applied. The pattern of the parameter K repeats a periodic variation in the set detection range as shown in FIG.

With the above-described algorithm, the signal processing unit 3 determines the posture and the behavior based on the ratio of the load to the weight of the subject and the time-series change pattern thereof.
Further, the result of the determination is transmitted to the external device 7 via the signal line 6 and can be displayed. However, the detection range described above can be set arbitrarily according to individual differences.

FIG. 6 is a circuit diagram of the signal processing section 3. In the figure, an amplifier 30 amplifies the output of the pressure sensor 1. The A / D converter 31 converts the amplified pressure sensor output into a digital signal. The circuits after the A / D converter are constituted by digital circuits. Parameter K operation circuit 3
2 calculates a parameter K which is a ratio of the load F applied to the pressure sensor 1 to the weight of the subject. When the parameter K is 100%, the subject is standing on one leg and standing still. The parameter K is calculated as a ratio based on the output of the pressure sensor 1 when one foot is standing.

The change detection circuit 33 sets the parameter K in FIG.
It is detected whether the temporal change shown in (A) to (C) occurs. When a temporal change is detected, a change detection signal S1
Is output. As shown in FIGS. 3A to 3C, no temporal change occurs when the subject is stationary, and in this case, the no-change detection signal S2 is output.

A threshold value generating circuit 34 outputs a threshold value of a parameter K for discriminating a standing position, a sitting position, and a supine position to a first judging circuit 35, and performs walking, stair climbing, and stair descending, respectively. The threshold value of the parameter K for determination is output to the second determination circuit 36. First judgment circuit 35
Determines the standing, sitting, and supine positions from the parameter K from the parameter K calculation circuit 32 when the no-change detection signal S2 is generated, and generates a determination result S3. When the change detection signal S2 is generated, the second determination circuit 36 determines walking, ascending, or descending from the parameter K from the parameter K operation circuit 32, and generates a determination result S4.
As described above, one of the determination circuits 35 and 36 operates according to the output of the change detection circuit 33.

The threshold values generated by the threshold value generation circuit 35 for discrimination between the standing position, the sitting position, and the supine position are 0, 50%, 1
This is a digital value of the parameter K indicating 00%. The threshold for discriminating between walking, climbing the stairs, and descending the stairs is a digital value of the parameter K indicating 50% and 100%.

The first determination circuit 35 compares the parameter K calculated when the no-change detection signal S1 is generated with the threshold value from the threshold value generation circuit 34, and stands by when it corresponds to the parameter of 0. When the calculated parameter K is 0% <K <50%, the sitting position is determined, and when the calculated parameter K is 50% ≦ K <100%, the supine position is determined.

The second determination circuit is provided with a change detection signal S2
Is detected, the peak value of the parameter K is detected, and the peak value is compared with the threshold value from the threshold value generation circuit 34. If the peak value is within 50%, it is determined that the stairs are climbed. When the peak value is 50% or more and within 100%, it is determined that the user is walking, and when the peak value is 100% or more, it is determined that the user is going down the stairs.

The determination results of the first and second determination circuits 35 and 36 are output to the external device 7, and the external device 7 executes predetermined processing according to the determination results.

FIG. 7 is an external view showing a second embodiment of the present invention. In FIG. 7, the physical activity measurement system
Pressure sensor 1 mounted on heel and signal amplification / transmission unit 9
, A signal line 2 connecting them, and a transmitting antenna 8
1, a receiving unit 11, a receiving antenna 10, the same signal processing unit 3 as in FIG. 1, a signal line 6, and an external device 7. The subject carries the pressure sensor 1, the signal amplification / transmission unit 9, and the transmission antenna 8.

Next, the operation will be described. In FIG. 7, a load signal measured by the pressure sensor 1 is amplified by a signal amplifying / transmitting unit 9 via a signal line 2 and modulated into a radio signal.
The signal is transmitted to the external receiving antenna 10 by the transmitting antenna 8. The receiving unit 11 demodulates the load signal and outputs the demodulated signal to the signal processing unit 3. The signal processing unit 3 determines the posture and the behavior of the person to be measured by the algorithm described in the first embodiment of the present invention, and outputs the result via the signal line 6 to the external device 7.
Output to

[0030]

The first effect is that information on the posture can be obtained. The reason is that it has a function of determining a posture from a load measured by a sensor mounted on the heel and a load pattern obtained based on the load.

The second effect is that it is possible to measure a movement accompanied by a weight shift, that is, an action accompanied by a foot movement. The reason is that it has a function of determining an action from a load measured by a sensor mounted on the heel and a load pattern obtained based on the load.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a front view showing a method of using the first embodiment of the present invention.

FIGS. 3A and 3B show a posture and a load ratio of the subject, wherein FIG. 3A shows a standing position, FIG. 3B shows a sitting position, and FIG. 3C shows a supine position.

FIGS. 4A and 4B show the behavior of the subject and the ratio of the load, wherein FIG. 4A shows a state of walking, FIG. 4B shows a state of climbing stairs, and FIG.

FIGS. 5A and 5B are waveform diagrams showing temporal changes in a parameter K of a load ratio, wherein FIG. 5A shows changes when walking, FIG. 5B shows changes when going up stairs, and FIG.

FIG. 6 is a circuit diagram illustrating a circuit configuration of a signal processing unit.

FIG. 7 is a front view showing a second embodiment of the present invention.

FIG. 8 is a block diagram of a conventional physical activity amount measurement system.

9 (a) and 9 (b) are perspective views showing a state change of a measuring unit in FIG. 8;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pressure sensor 2 signal line 3 signal processing unit 6 signal line 7 external device 8 transmitting antenna 9 signal amplifying / transmitting unit 10 receiving antenna 11 receiving unit

Claims (5)

(57) [Claims] 1. A pressure sensor for detecting a pressure applied to a heel of a person to be measured, and a ratio and a load pattern of a load applied to the heel based on the weight of the person to be measured are obtained based on a signal obtained from the pressure sensor. A signal processing unit for determining a posture and an action from the ratio and the load pattern , wherein the signal processing unit applies a load to the pressure sensor with respect to the weight of the subject.
Means for calculating a parameter K, which is a weight ratio, and detecting whether a temporal change occurs in the parameter K
When a temporal change is detected, a change detection signal is issued.
When there is no time change, a no-change detection signal is output.
A change detecting means to be generated, and when the no change detection signal is generated, the operation means
The standing, sitting, and supine positions are determined based on these parameters K.
A first determining means for generating a fixed result, and the calculating means when the change detection signal is generated.
Judgment of walking, climbing stairs, descending stairs from these parameters K
And a second determination means for generating a determination result . 2. The method according to claim 1, wherein the first determining means includes a standing position, a sitting position, and a supine position.
Threshold for determining the supine position
A value generating circuit, and comparing the threshold value with the parameter K.
Comparison circuit to determine standing, sitting and supine positions
The physical activity measurement system according to claim 1, comprising:
M 3. The method according to claim 2, wherein the second determining means includes:
Thresholds for discriminating down stairs
A threshold value generating circuit, the threshold value and the parameter
By comparing the peak values of TA, walking, climbing stairs,
2. The circuit according to claim 1, further comprising: a determination circuit for determining step-down.
Physical activity measurement system. 4. When the parameter K is 100%
In the state where the subject is standing still on one foot
And the calculating means is a pressure sensor when one leg is standing
The parameter K is expressed as a ratio based on the output of
4. The method according to claim 2, wherein
Physical activity measurement system. 5. A pressure for detecting a pressure applied to a heel of a subject.
A force sensor, and a wireless transmitter for transmitting an output of the pressure sensor as a wireless signal.
A signal means, said receiving means for receiving radio signals, the body of the subject based on a signal obtained from said receiving means
Percentage of load on heel based on weight and load putter
From the ratio and the load pattern.
A signal processing unit that determines a posture and an action, wherein the signal processing unit applies a load to the pressure sensor with respect to the weight of the subject.
Means for calculating a parameter K, which is a weight ratio, and detecting whether a temporal change occurs in the parameter K
When a temporal change is detected, a change detection signal is issued.
When there is no time change, a no-change detection signal is output.
A change detecting means to be generated, and when the no change detection signal is generated, the operation means
The standing, sitting, and supine positions are determined based on these parameters K.
A first determining means for generating a fixed result, and the calculating means when the change detection signal is generated.
Judgment of walking, climbing stairs, descending stairs from these parameters K
And a second determination means for generating a determination result
Activity measurement system.