JP2022021806A - Biological state monitoring system, bed system equipped with the same, and biological state monitoring method - Google Patents

Abstract

To provide an alternative system for monitoring a biological state of a subject by using a load detector.SOLUTION: A biological state monitoring system for monitoring a biological state of a subject on a bed includes: a first load detector provided on the bed or at the lower part of the leg of the bed on one side in a width direction of the bed for detecting a load, which is a load by the subject, including a load component that vibrates in response to a heart beat of the subject; a second load detector provided on the bed or at the lower part of the leg of the bed on the other side in the width direction of the bed for detecting a load, which is a load by the subject, including a load component that vibrates in response to a heart beat of the subject; and a heart beat state determination unit for obtaining a difference between the load by the subject detected by the first load detector and the load by the subject detected by the second load detector, and determining the heart beat state of the subject from the difference.SELECTED DRAWING: Figure 1

Description

The present invention relates to a biological condition monitoring system including a plurality of load detectors, a bed system including the system, and a biological condition monitoring method using a plurality of load detectors.

In the fields of medical care and long-term care, it has been proposed to detect the load of a subject on a bed via a load detector and determine the state of the subject based on the detected load. Specifically, for example, it has been proposed to estimate the respiratory rate and heart rate of a subject based on the detected load.

Patent Document 1 is provided with a filter, detects the cardiac motion of the test body from a frequency component having a high fluctuation output of the center of gravity position of the test body, and is tested from a frequency component having a low fluctuation output of the center of gravity position of the test body. It discloses a respiratory and cardiac motility measuring device that detects the respiratory motility of a living body. Patent Document 2 discloses an motion detection device capable of extracting a respiratory change cycle and outputting it as a respiratory frequency by processing a change in the position of the center of gravity of a user on a sleeping surface by a fast Fourier transform or the like. .. Further, Patent Document 3 issued to the present applicant discloses a method for obtaining the respiratory rate of a subject with high accuracy by using information on the temporal fluctuation of the position of the center of gravity of the subject on the bed and the body movement. ..

Special Publication No. 61-24010 Japanese Unexamined Patent Publication No. 2014-180432 Japanese Patent No. 6105703

It is an object of the present invention to provide an alternative system and method for monitoring the biological condition of a subject using a load detector.

According to the first aspect of the present invention,
A biological condition monitoring system that monitors the biological condition of a subject on the bed.
A first load detector provided under the bed or under the legs of the bed on one side in the width direction of the bed and detecting a load including a load component that is a load by the subject and vibrates according to the heartbeat of the subject.
A second load detector provided on the other side of the width direction of the bed under the bed or under the legs of the bed and detecting a load that is a load by the subject and includes a load component that vibrates according to the heartbeat of the subject.
A heartbeat state determination unit that obtains a difference between the load detected by the subject and the load detected by the second load detector by the first load detector and determines the heartbeat state of the subject from the difference. A biological condition monitoring system is provided.

In the biological condition monitoring system of the first aspect, the first load detector and the second load detector may be arranged symmetrically with respect to an axis extending in the length direction of the bed at the center in the width direction of the bed.

In the biological condition monitoring system of the first aspect, the second load detector may be provided on one side in the length direction of the bed, and the load detected by the second load detector by the subject is the subject's load. It may contain a load component that vibrates in response to breathing. Further, the biological condition monitoring system of the first aspect is further provided on the other side in the length direction of the bed under the bed or under the legs of the bed, and is a load by the subject and vibrates in response to the subject's breathing. A third load detector that detects a load including a load component may be included, and the difference between the load by the subject detected by the second load detector and the load by the subject detected by the third load detector is obtained. Further, it may be provided with a breathing state determining unit that determines the breathing state of the subject from the difference.

In the biological condition monitoring system of the first aspect, the first load detector may be provided on one side in the length direction of the bed, and the load detected by the first load detector by the subject is the subject's load. A load component that vibrates in response to breathing may be included, the third load detector may be provided on the other side in the width direction of the bed, and the load detected by the third load detector by the subject is the subject. It may contain a load component that vibrates according to the heartbeat of. The biological condition monitoring system of the first aspect is further provided under the bed or under the legs of the bed on one side in the width direction of the bed and the other side in the length direction of the bed, and is a load by the subject. A fourth load detector that detects a load including a load component that vibrates according to the subject's breath and a load component that vibrates according to the subject's heartbeat may be provided, and the heartbeat state determining unit may include a first load. The sum of the load by the subject detected by the detector and the load by the subject detected by the fourth load detector, and the load by the subject detected by the second load detector and detected by the third load detector. The difference from the sum of the loads by the subject may be obtained, and the heartbeat state of the subject may be determined from the difference. The difference between the sum of the loads by the subject detected by the second load detector, the load by the subject detected by the third load detector, and the sum of the loads by the subject detected by the fourth load detector. The breathing state of the subject may be determined from the difference.

According to the second aspect of the present invention,
A biological condition monitoring system that monitors the respiratory condition of a subject on the bed.
A first load detector provided under the bed or under the legs of the bed on one side in the length direction of the bed and detecting a load that is a load by the subject and includes a load component that vibrates in response to the subject's respiration. ,
With a second load detector provided on the other side of the length direction of the bed under the bed or under the legs of the bed and detecting a load by the subject including a load component that vibrates in response to the subject's respiration. ,
A respiratory state determining unit that obtains a difference between the load detected by the subject and the load detected by the second load detector by the first load detector and determines the respiratory state of the subject from the difference. A biological condition monitoring system is provided.

According to the third aspect of the present invention,
Bed and
A bed system comprising the biological condition monitoring system of the first aspect or the second aspect is provided.

According to the fourth aspect of the present invention,
It is a biological condition monitoring method that monitors the biological condition of the subject on the bed.
A first load detector provided on the bed or under the leg of the bed on one side in the width direction of the bed detects the load by the subject and includes the load component that vibrates according to the subject's heartbeat. When,
A second load detector provided on the other side of the width direction of the bed, which is provided on the bed or under the legs of the bed, detects the load by the subject and includes the load component which vibrates according to the subject's heartbeat. When,
A method including obtaining the difference between the load detected by the subject and the load detected by the second load detector by the first load detector and determining the heartbeat state of the subject from the difference. Provided.

In the biological condition monitoring method of the fourth aspect, the first load detector and the second load detector may be arranged symmetrically with respect to an axis extending in the length direction of the bed at the center in the width direction of the bed.

In the biological condition monitoring method of the fourth aspect, the second load detector may be provided on one side in the length direction of the bed, and the load detected by the second load detector by the subject is the subject's load. It may contain a load component that vibrates in response to breathing. Further, the biological condition monitoring method of the fourth aspect is a load by the subject by a third load detector provided on the bed or under the legs of the bed on the other side in the length direction of the bed, and the subject's breathing. It may further include detecting a load including a load component that vibrates accordingly, and the difference between the load by the subject detected by the second load detector and the load by the subject detected by the third load detector. It may include determining the respiratory state of the subject from the difference.

In the biological condition monitoring method of the fourth aspect, the first load detector may be provided on one side in the length direction of the bed, and the load detected by the first load detector by the subject is the subject's load. A load component that vibrates in response to breathing may be included, the third load detector may be provided on the other side in the width direction of the bed, and the load detected by the third load detector by the subject is the subject. It may contain a load component that vibrates according to the heartbeat of. Further, the biological condition monitoring method of the fourth aspect is further carried out by the subject by a fourth load detector provided under the bed or the leg of the bed on one side in the width direction of the bed and the other side in the length direction of the bed. The load may include detecting a load including a load component that vibrates in response to the subject's breath and a load component that vibrates in response to the subject's heartbeat, and determines the heartbeat state of the subject. Is the sum of the load by the subject detected by the first load detector and the load by the subject detected by the fourth load detector, and the load by the subject and the third load detected by the second load detector. The difference from the sum of the loads by the subject detected by the detector may be obtained, and the heartbeat state of the subject may be determined from the difference. The sum of the load by the subject detected by the load detector and the load by the subject detected by the second load detector, and the load by the subject detected by the third load detector and detected by the fourth load detector. The difference from the sum of the loads by the subject may be obtained, and the respiratory state of the subject may be determined from the difference.

According to the fifth aspect of the present invention,
It is a biological condition monitoring method that monitors the respiratory condition of the subject on the bed.
A first load detector provided on the bed or under the legs of the bed on one side in the length direction of the bed detects the load by the subject and includes the load component that vibrates in response to the subject's breathing. That and
A second load detector provided on the bed or under the leg of the bed on the other side in the length direction of the bed detects the load by the subject and includes the load component that vibrates in response to the subject's breathing. That and
A biological state including obtaining the difference between the load detected by the subject and the load detected by the second load detector by the first load detector and determining the respiratory state of the subject from the difference. A monitoring method is provided.

INDUSTRIAL APPLICABILITY According to the present invention, an alternative system and method for monitoring the biological condition of a subject using a load detector are provided.

FIG. 1 is a block diagram showing a configuration of a biological condition monitoring system according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing the arrangement of the load detector with respect to the bed. FIG. 3 is a flowchart showing a biological condition monitoring method using a biological condition monitoring system. FIG. 4 is an explanatory diagram for explaining the state of the load signal from each of the load detectors arranged at the four corners of the bed. The central figure is a schematic plan view showing the positional relationship between the bed, the subject lying on the bed, and the load detectors arranged at the four corners of the bed. The lower right, lower left, upper left, and upper right graphs are graphs showing the waveforms of load signals from load detectors arranged in the lower right, lower left, upper left, and upper right corners of the bed, respectively. The waveform in each graph is shown separately as a waveform showing a load component that vibrates according to the respiration of the subject and a waveform showing a load component that vibrates according to the heartbeat of the subject. FIG. 5 is a graph showing an example of a breathing signal which is a difference between a load signal from a load detector arranged on the leg side of a subject and a load signal from a load detector arranged on the head side of the subject. .. FIG. 6 is a graph showing an example of a heartbeat signal which is a difference between a load signal from a load detector arranged on the right side of the subject and a load signal from the load detector arranged on the left side of the subject. 7 (a) to 7 (d) are examples of the load signal of the subject detected by the load detection unit of the biological condition monitoring system of the embodiment. 7 (a), 7 (b), 7 (c), and 7 (d) show the load signals detected by the load detectors located at the lower right, lower left, upper left, and upper right of the subject, respectively. It is a graph which shows an example. FIG. 8 is a graph showing a respiratory signal which is a difference between the load signals shown in FIGS. 7 (a) to 7 (d). In FIG. 9, the load signals shown in FIGS. 7 (a) to 7 (d) are detected during the same period as the period in which the load signals shown in FIGS. 7 (a) to 7 (d) are detected. It is a graph which shows the result of the measurement using the respiratory flow meter performed on the same subject as the subject. 10 (a), 10 (b), 10 (c), and 10 (d) are shown in FIGS. 7 (a), 7 (b), 7 (c), and 7 (d), respectively. It is a graph which enlarged a part of the graph shown. FIG. 11 is a graph showing a heartbeat signal which is a difference between the load signals shown in FIGS. 10A to 10D. In FIG. 12, the load signals shown in FIGS. 10 (a) to 10 (d) are detected during the same period as the period in which the load signals shown in FIGS. 10 (a) to 10 (d) are detected. It is a graph which shows the result of the measurement using the fingertip sphygmomanometer performed on the same subject as the subject. FIG. 13 is a block diagram showing the overall configuration of the bed system according to the modified example.

<Embodiment>
An embodiment of the present invention will be described as an example in which a biological condition monitoring system 100 having the configuration shown in FIG. 1 is used together with the bed BD shown in FIG. 2 to monitor the respiratory condition and the heartbeat condition of a subject.

In the following description, the center of the rectangular bed BD is the center O, the axis extending through the center O and extending in the lateral direction (width direction) of the bed BD is the X axis of the bed BD, and the length of the bed BD passing through the center O. The axis extending in the (length direction, vertical direction) is the Y axis of the bed BD. In the plan view of the bed BD, the right side of the center O of the bed BD is the positive side of the X axis, the left side is the negative side of the X axis, the lower side of the center O of the bed BD is the positive side of the Y axis, and the upper side is the Y axis. Negative side. When the subject S lies on the bed BD, he generally lies along the Y-axis, with his head on the negative side in the Y-axis direction and his legs on the positive side.

As shown in FIG. 1, the biological condition monitoring system 100 of the present embodiment mainly includes a load detection unit 1 and a biological condition determination unit 3. The load detection unit 1 and the biological state determination unit 3 are connected via an A / D conversion unit 2. A storage unit 4, a display unit 5, a notification unit 6, and an input unit 7 are further connected to the biological state determination unit 3.

The load detector 1 includes four load detectors 1a, 1b, 1c, and 1d (first load detector, second load detector, third load detector, fourth load detector). Each of the load detectors 1a, 1b, 1c, and 1d is a load detector that detects a load using, for example, a beam-shaped load cell. Such load detectors are described, for example, in Japanese Patent No. 4829020 and Japanese Patent No. 4002905. The load detectors 1a, 1b, 1c, and 1d are each connected to the A / D conversion unit 2 by wiring.

The four load detectors 1a, 1b, 1c, and 1d of the load detection unit 1 are arranged under the legs of the bed used by the subject. Specifically, for example, the load detectors 1a, 1b, 1c, and 1d are respectively arranged under the casters C attached to the lower ends of the legs at the four corners of the bed BD, as shown in FIG. In the present embodiment, the load detectors 1a, 1b, 1c, and 1d are the positive side in the X-axis direction and the positive side in the Y-axis direction, the negative side in the X-axis direction and the positive side in the Y-axis direction, and the negative side in the X-axis direction, respectively, of the bed BD. It is arranged under the caster C on the side and the negative side in the Y-axis direction, and on the positive side in the X-axis direction and the negative side in the Y-axis direction.

The load detectors 1a and 1b are installed at positions symmetrical with respect to the Y axis, that is, equidistant from the Y axis. Similarly, the load detectors 1c and 1d are installed at positions symmetrical with respect to the Y axis, that is, installed equidistant from the Y axis. Further, the load detectors 1a and 1d are installed at positions symmetrical with respect to the X axis, that is, installed equidistant from the X axis. Similarly, the load detectors 1b and 1c are installed at positions symmetrical with respect to the X axis, that is, installed equidistant from the X axis.

The A / D conversion unit 2 includes an A / D converter that converts an analog signal from the load detection unit 1 into a digital signal, and is connected to the load detection unit 1 and the biological state determination unit 3 by wiring, respectively.

The biological state determination unit (control unit) 3 determines the biological state of the subject, for example, the respiratory state and the heartbeat state, based on the load signal from the load detection unit 1. In the present embodiment, the biological state determining unit 3 includes a respiratory state determining unit 31 for determining a respiratory state and a heartbeat state determining unit 32 for determining a heartbeat state. The biological state determination unit (control unit) 3 may be a dedicated or general-purpose computer. The details of the determination of the biological condition of the subject in the biological condition determination unit 3 will be described later.

The storage unit 4 is a storage device for storing data used in the biological condition monitoring system 100, and for example, a hard disk (magnetic disk) can be used.

The display unit 5 is a monitor such as a liquid crystal monitor that displays the biological condition of the subject output from the biological condition determination unit 3 to the user of the biological condition monitoring system 100. The notification unit 6 includes a device that aurally performs a predetermined notification based on an output (information about the biological condition, etc.) from the biological state determination unit 3, for example, a speaker. The input unit 7 is an interface for performing a predetermined input to the biological condition monitoring system 100, and may be a keyboard and a mouse.

A method of monitoring the biological condition of a subject on a bed by using such a biological condition monitoring system 100 will be described. Here, the biological state of the subject is specifically, for example, the respiratory state and / or the heartbeat state of the subject.

As shown in the flowchart of FIG. 3, the determination of the biological condition of the subject using the biological condition monitoring system 100 is performed by the load detection step S1 for detecting the load of the subject and the respiration of the subject based on the fluctuation of the detected load of the subject. Respiratory state determination step S2 for determining the state, heart rate state determination step S3 for determining the subject's heartbeat state based on the detected load fluctuation of the subject, and display step S4 for displaying the determined respiratory state and heartbeat state. Mainly includes.

[Load detection process]
In the load detection step S1, the load of the subject S on the bed BD is detected by using the load detectors 1a, 1b, 1c, and 1d. Since each of the load detectors 1a, 1b, 1c, and 1d is arranged under each leg of the bed BD, the load applied to the upper surface of the bed BD is the four load detectors 1a, 1b, 1c, 1d. It is detected in a distributed manner. In particular, if the center of load (center of gravity) is located at the center O of the bed BD, the four load detectors 1a, 1b, 1c, and 1d are uniformly dispersed and detected.

The load detectors 1a, 1b, 1c, and 1d each detect a load (load change) and output it as an analog signal to the A / D conversion unit 2. The A / D conversion unit 2 converts an analog signal into a digital signal with a sampling period of, for example, 5 milliseconds, and outputs the digital signal (hereinafter referred to as “load signal”) to the biological state determination unit 3. In the following, the load signals output from the load detectors 1a, 1b, 1c, and 1d and digitally converted by the A / D conversion unit 2 are referred to as load signals sa, sb, sc, and sd, respectively.

[Respiratory state determination process, heart rate state determination process]
In the respiratory state determination step S2 and the heartbeat state determination step S3 (both are collectively referred to as a "biological state determination step"), the respiratory state determination unit 31 and the heartbeat state determination unit 32 of the biological state determination unit 3 are subjected to load signals sa to Based on sd, the respiratory state and heartbeat state of the subject S are determined.

Human breathing is performed by moving the thorax and diaphragm to inflate and contract the lungs. Here, during inspiration, that is, when the lungs expand, the diaphragm descends and the internal organs also move downward. On the other hand, when exhaling, that is, when the lungs contract, the diaphragm rises upward and the internal organs also move upward. According to a study on breathing, the inventor of the present invention vibrates the subject's center of gravity substantially along the subject's vertical direction (direction of the spine), that is, the direction in which the subject's body axis extends, due to the vertical movement of the internal organs in response to breathing. I found out to do.

Hereinafter, the vibration of the center of gravity of the subject along the body axis direction of the subject according to the breathing of the subject is referred to as “breathing vibration”. As shown by the double-headed arrow b in FIG. 4, the center of gravity G of the subject S vibrates along the direction of the body axis SA of the subject S due to the respiratory vibration. The vibration amount (amplitude) of the respiratory vibration indicated by the double-headed arrow b is exaggerated for the sake of explanation.

Further, the inventor of the present invention has found that the center of gravity of the subject vibrates slightly in the direction orthogonal to the body axis of the subject, and finds that this vibration corresponds to the heartbeat of the subject. ..

That is, according to the findings of the inventor of the present invention, the center of gravity of the subject vibrates in a uniaxial direction different from the body axis direction of the subject with the heartbeat of the subject (beating of the heart, that is, contraction and expansion of the heart). ing. Therefore, the heartbeat has a vibration component in the direction orthogonal to the body axis direction of the subject, and the center of gravity of the subject also has a component that slightly vibrates in the direction orthogonal to the body axis of the subject.

Hereinafter, the vibration of the center of gravity of the subject along the uniaxial direction different from the body axis direction of the subject according to the heartbeat of the subject is referred to as “heartbeat vibration”. Further, the component that vibrates in the direction orthogonal to the body axis direction of the subject, which is included in the heartbeat vibration, is called a heartbeat vibration component. The heartbeat vibration component of the subject S is shown by the double-headed arrow h in FIG. The vibration amount (amplitude) of the heartbeat vibration component indicated by the double-headed arrow h is also exaggerated for explanation.

The inventor of the present invention has a specific phase relationship in which each of a plurality of load signals from a plurality of load detectors arranged to detect a load from a subject on the bed has a specific phase relationship according to the subject's respiratory vibration and heartbeat vibration. By the following principle, it is possible to determine the respiratory state and / or the heartbeat state of the subject without calculating the position of the center of gravity of the subject by simply obtaining the difference between multiple load signals. I found it.

FIG. 4 shows the load signal sa when the subject S is lying on the bed BD with the body axis SA coincided with the Y axis and the vibration origin of the respiratory vibration coincided with the center O of the bed BD. The state of change in each of ~ sd in a predetermined 5 seconds is shown. In addition, no body movement other than respiration and heartbeat occurred in the subject S in these 5 seconds.

Each of the load signals sa to sd is a load component (hereinafter referred to as "respiratory component") that changes according to the subject's breathing (respiratory vibration) and the subject's heartbeat (heartbeat vibration, more specifically, the heartbeat vibration component). ) Includes a load component (hereinafter referred to as "heartbeat component") that vibrates in response to the above. In FIG. 4, for convenience of explanation, each of the load signals sa to sd is shown in a state where the respiratory component and the heartbeat component are frequency-separated.

The lower right graph of FIG. 4 shows the respiratory component sa _b and the heart rate component sa _h included in the load signal sa output from the load detector 1a. Similarly, the lower left graph of FIG. 4 shows the respiratory component sb _b and the heartbeat component sb _h included in the load signal sb output from the load detector 1b, and the upper left graph of FIG. 4 is output from the load detector 1c. The respiratory component sc _b and the heartbeat component sc _h included in the applied load signal sc are shown, and the graph on the upper right of _FIG . 4 shows the respiratory component sdb and the heartbeat component sd included in the load signal sd output from the load detector 1d. Indicates _h .

Specifically, the state of fluctuation of each signal (shape of signal waveform) is as follows.

Since the respiratory components sa _b to _sdb all vibrate (variate) in response to the respiratory vibration of the subject S, the vibration cycles are equal to each other and represent the respiratory cycle of the subject S.

From the respiratory component sa _b included in the load signal sa from the load detector 1a arranged on the leg side (positive side in the Y-axis direction) of the subject S and the load detector 1b arranged on the leg side of the subject S. It is in phase with the respiratory component sb _b included in the load signal sb. This is because, as described above, the moving direction of the center of gravity G due to the breathing of the subject S is in the direction of the body axis SA of the subject S, that is, in the Y-axis direction, and the load detector 1a and the load detector 1b are in the Y-axis direction. This is because they are located on the same side with respect to the position of the center of gravity G of the subject S. It has been demonstrated from the experimental examples described later that the respiratory component sa _b and the respiratory component s _{b b} are in phase with each other (see FIGS. 7 (a) to 7 (d); FIGS. 7 (a) to 7 (7)). (D) is a waveform including a respiratory component and a heartbeat component, but as will be described later, since the amplitude of the respiratory component is larger than the amplitude of the heartbeat component, FIGS. 7 (a) to 7 (d) show. The phase relationship between each respiratory component can be read).

For the same reason, the respiratory component sc _b included in the load signal sc from the load detector 1c placed on the head side (negative side in the Y-axis direction) of the subject S and the load placed on the head side of the subject S. It is in phase with the respiratory component _sdb included in the load signal sd from the detector 1d.

Respiratory components sa _b and sb _b included in the load signals sa and sb from the load detectors 1a and 1b arranged on the leg side (positive side in the Y-axis direction) of the subject S, and the head side (Y-axis) of the subject S. The phases of the load signals sc from the load detectors 1c and 1d arranged on the negative side of the direction) and the respiratory components sc _b and sd _b included in the sd are reversed from each other. This is because the moving direction of the center of gravity G due to the breathing of the subject S is in the direction of the body axis SA of the subject S, that is, in the Y-axis direction, and the load detectors 1a and 1b and the load detectors 1c and 1d are in the Y-axis direction. This is because it is located on the opposite side of the position of the center of gravity G of the subject S. It has been demonstrated from the experimental examples described later that the respiratory components sa _b and sb _b and the respiratory components s b _c and sc _c have opposite phases (see FIGS. 7 (a) to 7 (d)).

Since the heartbeat components sa _h to sd _h all vibrate (variate) according to the heartbeat vibration component of the subject S, the vibration cycles are equal to each other and represent the heartbeat cycle of the subject S.

The heartbeat component sa _h included in the load signal sa from the load detector 1a arranged on the right side (positive side in the X-axis direction) of the subject S, and the load signal from the load detector 1d arranged on the right side of the subject S. It is in phase with the heartbeat component _sdh contained in sd. This is because, as described above, the component of the movement of the center of gravity G due to the heartbeat of the subject S (heartbeat vibration component) is in the direction orthogonal to the body axis of the subject, that is, in the X-axis direction, and the load detector 1a is in the X-axis direction. This is because 1d is located on the same side with respect to the center of gravity G of the subject S.

For the same reason, the heartbeat component sb _h contained in the load signal sb from the load detector 1b arranged on the left side (negative side in the X-axis direction) of the subject S and the load detector arranged on the left side of the subject S. It is in phase with the heartbeat component sc _h included in the load signal sc from 1c.

The heart rate components sa _h and sd _h included in the load signals sa and sd from the load detectors 1a and 1d arranged on the right side of the subject S (on the positive side in the X-axis direction) and the left side of the subject S (in the X-axis direction). The phases of the load signals sb from the load detectors 1b and 1c arranged on the negative side) and the respiratory components sb _h and sc _h included in sc are reversed from each other. This is because the component of the movement of the center of gravity G due to the heartbeat of the subject S (heartbeat vibration component) is in the direction orthogonal to the body axis of the subject, that is, in the X-axis direction, and the load detectors 1a and 1d and the load detection are performed in the X-axis direction. This is because the vessels 1b and 1c are located on the opposite sides of the position of the center of gravity G of the subject S.

Comparing the respiratory components sa _b to _sdb and the heart rate components sa _h to sd _h , the cycle of the respiratory components sa _b to _sdb is longer than the cycle of the heart rate components sa _h to sd _h . This is because the number of human breaths is about 12 to 20 times per minute, and the cycle is about 3 to 5 seconds (frequency is about 0.2 to 0.33 Hz), whereas the number of human heartbeats, That is, the heart rate is about 30 to 200 times per minute, and the cycle is about 0.3 to 2 seconds (frequency is about 0.5 to 3.3 Hz).

Further, in general, the amount of movement of the center of gravity due to respiratory vibration is larger than the amount of movement of the center of gravity due to heartbeat vibration. Therefore, the amplitude of the respiratory component is larger than the amplitude of the heartbeat component.

Based on the fact that each of the load signals sa to sd contains such a respiratory component and a heartbeat component, the respiratory state and the heartbeat state of the subject can be determined by obtaining the difference between the load signals.

For the breathing state, the difference between the load signal from the load detector arranged on one side in the Y-axis direction and the load signal from the load detector arranged on the other side in the Y-axis direction is obtained, and the difference is used. Can be decided. Specifically, for example, the sum of the load signals sa and sb from the load detectors 1a and 1b on the positive side in the Y direction and the sum of the load signals sc and sd from the load detectors 1c and 1d on the negative side in the Y direction. By obtaining the difference, the breathing state (breathing signal SB) of the subject S is determined. Expressing this as an equation is SB = sa + sb-sc-sd (Equation 1).

In the sum of the load signal sa and the load signal sb, the respiratory component sa _b and the respiratory component sb _b strengthen each other because they are in the same phase, and the heartbeat component sa _h and the heartbeat component sb _h cancel each other out because they are in the opposite phase. .. Similarly, in the sum of the load signal sc and the load signal sd, the respiratory component sc _b and the respiratory component _sdb are strengthened because they are in the same phase, and the heartbeat component sc _h and the heartbeat component sd _h are in opposite phases. Cancel each other. In the difference between the sum of the load signal sa and the load signal sb and the sum of the load signal sc and the load signal sd, the respiratory components sa _b and sb _b and the respiratory components sc _b and _sdb are in opposite phases, so that they are strengthened.

The respiratory signal SB (= sa + sb-sc-sd) is shown in FIG. The vibration cycle of the respiratory signal SB is equal to the period of the respiratory components sa _b to _sdb of the load signal sa to sd, and the amplitude is the sum of the absolute values of the amplitudes of the respiratory components sa _b to _sdb according to Equation 1. .. In FIG. 5, the amplitude of the respiratory signal SB is drawn compressed in comparison with the sum of the absolute values of the amplitudes of the respiratory components sa _b to sdb shown in _FIG .

Based on the cycle of the respiratory signal SB, the respiratory rate of the subject S and the like can be calculated. Specifically, one cycle of the breathing signal SB corresponds to one breathing of the subject S. That is, the respiratory signal SB itself represents the respiratory state of the subject S, and a more detailed respiratory state can be determined based on the respiratory signal SB.

For the heartbeat state, the difference between the load signal from the load detector arranged on one side in the X-axis direction and the load signal from the load detector arranged on the other side in the X-axis direction is obtained, and the difference is used. Can be decided. Specifically, for example, the sum of the load signals sa and sd from the load detectors 1a and 1d on the positive side in the X direction and the sum of the load signals sb and sc from the load detectors 1b and 1c on the negative side in the X direction. By obtaining the difference, the heartbeat state (heartbeat signal SH) of the subject S is determined. Expressing this as an equation is SH = sa-sb-sc + sd (Equation 2).

In the sum of the load signal sa and the load signal sd, the heartbeat component _{sa h} and the heartbeat component _{sd h} are in phase with each other, so that they are strengthened. .. Similarly, in the sum of the load signal sb and the load signal sc, the heartbeat component sb _h and the heartbeat component sc _h are in phase with each other and thus strengthen each other, and the respiratory component sb _b and the respiratory component sc _b are in opposite phase. Cancel each other. In the difference between the sum of the load signal sa and the load signal sd and the sum of the load signal sb and the load signal sc, the heartbeat components sa _h and _{sdh and the heartbeat components sb h and sc h are in} opposite phases, so that they strengthen each other. ..

The heart rate signal SH (= sa-sb-sc + sd) is shown in FIG. The vibration cycle of the heartbeat signal SH is equal to the cycle of the heartbeat components sa _h to _sdh of the load signals sa to sd, and the amplitude is the sum of the absolute values of the amplitudes of the heartbeat components sa _h to sd _h according to Equation 2. be. In FIG. 6, the amplitude of the heartbeat signal SH is drawn compressed in comparison with the sum of the absolute values of the amplitudes of the heartbeat components _sah to _sdh shown in FIG.

From the cycle of the heart rate signal SH, the heart rate and the like of the subject S can be calculated. Specifically, one cycle of the heartbeat signal SH corresponds to one heartbeat of the subject S. That is, the heartbeat signal SH itself represents the heartbeat state of the subject S, and a more detailed heartbeat state can be determined based on the heartbeat signal SH.

In the above, regarding the principle that the biological state determining unit 3 determines the respiratory state and the heartbeat state of the subject S, the subject S makes the body axis SA coincide with the Y axis of the bed BD on the center O of the bed BD. The case of lying on the back was explained as an example. However, the determination of the respiratory state and the heartbeat state of the subject S based on the above principle can be performed even if the position of the subject S changes. The determination of the respiratory state and the heartbeat state of the subject S based on the above principle is feasible as long as the direction of the body axis SA of the subject S substantially coincides with the Y-axis direction (longitudinal direction) of the bed BD.

Further, the determination of the respiratory state of the subject S can be performed even when the body axis SA of the subject S is tilted to some extent with respect to the Y-axis direction of the bed BD. This is because the amplitude of the heartbeat vibration is smaller than the amplitude of the respiratory vibration, and even if the direction of the body axis SA, that is, the vibration direction of the respiratory vibration is tilted to some extent with respect to the Y axis, the Y-axis direction component of the respiratory vibration is significant. This is because it can be detected with a large size.

7 (a) to 7 (d) show the load signals sa to sd detected in a certain period (0s to 60s) by the load detection unit 1 of the biological condition monitoring system 100 of the present embodiment. The respiratory state determination unit 31 receives such load signals sa to sd from the load detection unit 1 and determines the respiratory state based on these.

First, the respiratory state determination unit 31 calculates (acquires) the respiratory signal SB by obtaining the difference (sa + sb-sc-sd) between the sum of the load signal sa and the load signal sb and the sum of the load signal sc and the load signal sd. .. The calculated respiratory signal SB is shown in FIG.

Here, the respiratory flow rate performed on the same subject S during the same period (0s to 60s) when the load signals sa to sd shown in FIGS. 7 (a) to 7 (d) were detected. The result of the measurement using the meter (respiratory flow rate waveform) is shown in FIG. As the respiratory flow meter, a differential pressure transducer TP-602T manufactured by Nihon Kohden Co., Ltd. was used.

Based on the comparison between the respiratory signal SB of FIG. 8 and the respiratory flow rate waveform of FIG. 9, the following can be said.
(1) The cycle of the respiratory signal SB is substantially equal to the cycle of the respiratory flow waveform.
(2) There is a correlation between the amplitude of the respiratory signal SB and the amplitude of the respiratory flow waveform. Specifically, during the period in which the breathing flow waveform vibrates with substantially the same amplitude per 0 to 20 seconds, the breathing signal SB also vibrates with substantially the same amplitude. At the time when the amplitude of the respiratory flow rate waveform is large at 35 seconds and 50 seconds, the amplitude of the respiratory signal SB is also large. At the time when the amplitude of the respiratory flow rate waveform per 30 seconds and 45 seconds is small, the amplitude of the respiratory signal SB is also small.

From such a correspondence between the respiration signal SB and the respiration flow waveform, it can be seen that the respiration signal SB reflects the respiration state of the subject S at least to the same extent as the respiration flow waveform (contains information on respiration). .. Therefore, the calculation of the respiratory rate or the like based on the respiratory signal SB can be performed with the same or higher accuracy as the calculation of the respiratory rate or the like based on the respiratory flow waveform.

Further, the respiratory ventilation volume (tidal volume) of the subject can be obtained based on the area of the respiratory flow flow waveform shown in FIG. 9, but since the respiratory signal SB has the above-mentioned correspondence relationship with the respiratory flow flow waveform, the respiratory signal It is also possible to calculate the respiratory ventilation of the subject based on the area of the SB waveform.

10 (a) to 10 (d) show load signals sa to sd detected in a certain period (20s to 30s) by the load detection unit 1 of the biological condition monitoring system 100 of the present embodiment. The heartbeat state determination unit 32 receives such load signals sa to sd from the load detection unit 1 and determines the heartbeat state based on these.

First, the heart rate state determination unit 32 calculates (acquires) the heart rate signal SH by obtaining the difference (sa-sb-sc + sd) between the sum of the load signal sa and the load signal sd and the sum of the load signal sb and the load signal sc. do. The calculated heart rate signal SH is shown in FIG.

Here, the fingertip blood pressure performed on the same subject S during the same period (20s to 30s) when the load signals sa to sd shown in FIGS. 10 (a) to 10 (d) were detected. The result of the measurement (fingertip blood pressure waveform) using the meter (NIBP) is shown in FIG. As the fingertip sphygmomanometer, a human NIBP system (model ML282-SS) manufactured by BioResearch Center Co., Ltd. was used.

Based on the comparison between the heart rate signal SH in FIG. 11 and the fingertip blood pressure waveform in FIG. 12, the following can be said.
(1) The cycle of the heartbeat signal SH is substantially equal to the cycle of the fingertip blood pressure waveform.
(2) There is a correlation between the amplitude of the heart rate signal SH and the amplitude of the fingertip blood pressure waveform. Specifically, the amplitude of the fingertip blood pressure waveform and the amplitude of the heartbeat signal SH are almost the same in time.

From such a correspondence between the heartbeat signal SH and the fingertip blood pressure waveform, it can be seen that the heartbeat signal SH reflects the heartbeat state of the subject S at least to the same extent as the fingertip blood pressure waveform (contains information on the heartbeat). .. Therefore, the calculation of the heart rate or the like based on the heart rate signal SH can be performed with the same or higher accuracy as the calculation of the heart rate or the like based on the fingertip blood pressure waveform.

Further, the cardiac output of the subject can be obtained based on the fingertip blood pressure waveform shown in FIG. 12, but since the cardiac output SH has the above-mentioned correspondence with the fingertip blood pressure waveform, the subject is based on the waveform of the heartbeat signal SH. It is also possible to calculate the cardiac output of.

[Display process]
In the display step S4, the biological state determination unit 3 displays the respiratory state determined in the respiratory state determination step S2 and the heartbeat state determined in the heartbeat state determination step S3 on the display unit 5 which is a liquid crystal monitor as an example. The respiratory state and heart rate state of the subject S displayed on the display unit 5 may be the waveforms of the respiratory signal SB and the heart rate signal SH, and the respiratory rate, the respiratory ventilation volume, the heart rate, and the heart derived based on these may be used. It may be a stroke amount or the like.

The effects of the biological condition monitoring system 100 and the biological condition monitoring method of the present embodiment are summarized below.

The biological condition monitoring system 100 of the present embodiment obtains the difference between a plurality of load signals from a plurality of load detectors without calculating the position of the center of gravity of the subject S as in the prior art. The respiratory state and heartbeat state of the subject S can be determined. Therefore, the system configuration can be simplified.

Since the biological condition monitoring system 100 and the biological condition monitoring method of the present embodiment determine the respiratory condition and the heartbeat state of the subject S without calculating the position of the center of gravity of the subject S, the burden of arithmetic processing is small.

The biological condition monitoring system 100 and the biological condition monitoring method of the present embodiment take the difference between a plurality of load signals from a plurality of load detectors and strengthen the respiratory components contained in each of the plurality of load signals to enhance the respiratory signal. Seeking. Further, the heartbeat signal is obtained by taking the difference between the plurality of load signals from the plurality of load detectors and strengthening the heartbeat components contained in each of the plurality of load signals. Therefore, even if the subject S is in an unbalanced position on the bed BD and the strength of the load signal output from a certain load detector is not sufficient, a breathing signal having sufficient strength (a signal indicating a breathing state). And the heart rate signal (signal indicating the heart rate state) can be calculated (acquired).

The biological condition monitoring system 100 and the biological condition monitoring method of the present embodiment can satisfactorily determine the respiratory condition even if the body axis SA is tilted to some extent with respect to the Y axis.

The following modifications can also be used in the biological condition monitoring system 100 and the biological condition monitoring method of the above embodiment.

In the biological condition monitoring system 100 and the biological condition monitoring method of the above embodiment, in the respiratory condition determination step S2 executed by the biological condition determination unit 3, the load signal sa from the load detector 1a and the load signal from the load detector 1b The difference between the sum of sb and the sum of the load signal sc from the load detector 1c and the load signal sd from the load detector 1d was obtained to obtain the breathing signal SB. However, the present invention is not limited to this, and the breathing signal SB can also be obtained by obtaining the difference between one of the load signal sa and the load signal sb and one of the load signal sc and the load signal sd. In this case as well, by obtaining the difference, the respiratory components having opposite phases are strengthened.

Similarly, the heart rate signal SH can be obtained by obtaining the difference between one of the load signal sa and the load signal sd and one of the load signal sb and the load signal sc. In this case as well, by obtaining the difference, the heartbeat components having opposite phases are strengthened. In this case, it is desirable to use the difference between the load signal sa and the load signal sb or the difference between the load signal sd and the load signal sc so that the respiratory components having the same phase cancel each other out by obtaining the difference. ..

In the biological condition determination unit 3 of the biological condition monitoring system 100 of the above embodiment, after the respiratory condition determination unit 31 determines the respiratory condition of the subject S, the heartbeat condition determination unit 32 determines the heartbeat state of the subject S. Not limited to this. The heart rate state determination unit 32 may determine the heart rate state of the subject S first, or the breathing state determination unit 31 determines the breathing state of the subject S and the heart rate state determination unit 32 determines the heart rate state of the subject S. It may be done at the same time (in parallel).

The biological condition determination unit 3 of the biological condition monitoring system 100 of the above embodiment includes both the respiratory condition determination unit 31 and the heartbeat condition determination unit 32, but the present invention is not limited to this. The biological state determining unit 3 may have only one of the respiratory state determining unit 31 and the heartbeat state determining unit 32.

In the biological condition monitoring system 100 of the above embodiment, the load detection unit 1 includes four load detectors 1a to 1d, but the present invention is not limited to this. The load detection unit 1 may include at least two load detectors.

When there are two load detectors, for example, a first load detector is provided on the positive side in the X-axis direction, and a second load detector is provided on the negative side in the X-axis direction. Thereby, the difference between the load signal from the first load detector and the load signal from the second load detector can be obtained, and the heartbeat state of the subject S on the bed BD can be determined from the difference. It is desirable that the positions of the first load detector and the second load detector in the Y-axis direction are substantially the same. With such an arrangement, when the subject S is present at an intermediate position between the first load detector and the second load detector, the respiratory component is good in the difference between the load signals from both load detectors. It will be canceled. Further, it is more desirable to arrange the first load detector and the second load detector symmetrically with respect to the Y axis. With such an arrangement, when the body axis of the subject S coincides with the Y axis, the respiratory component is satisfactorily canceled in the difference between the load signals from both load detectors.

Alternatively, the first load detector may be provided on the positive side in the Y-axis direction, and the second load detector may be provided on the negative side in the Y-axis direction. Thereby, the difference between the load signal from the first load detector and the load signal from the second load detector can be obtained, and the breathing state of the subject S on the bed BD can be determined from the difference.

When there are three load detectors, for example, the biological condition monitoring system 100 of the above embodiment may have a configuration excluding the load detector 1d. In this case, for example, the difference between the load signal sa from the load detector 1a and the load signal sb from the load detector 1b is obtained, the heartbeat state of the subject S is determined from the difference, and the load from the load detector 1b is determined. The difference between the signal sb and the load signal sc from the load detector 1c can be obtained, and the respiratory state of the subject S can be determined from the difference.

In the biological condition monitoring system 100 of the above embodiment, the load detectors 1a, 1b, 1c, and 1d are not limited to the load sensor using the beam type load cell, and for example, a force sensor can also be used.

In the biological condition monitoring system 100 of the above embodiment, each of the load detectors 1a to 1d is arranged under the caster C attached to the lower end of the leg of the bed BD, but the present invention is not limited to this. Each of the load detectors 1a to 1d may be provided between the four legs of the bed BD and the floor plate of the bed BD, or if the four legs of the bed BD can be divided into upper and lower parts, the upper part may be provided. It may be provided between the leg and the lower leg. Further, the load detectors 1a to 1d may be integrally or detachably combined with the bed BD to form a bed system BDS including the bed BD and the biological condition monitoring system 100 of the present embodiment (FIG. 13). In the present specification and the present invention, the "load detector provided on the bed" refers to the load detector provided between the four legs of the bed BD and the floor plate of the bed BD as described above. It means a load detector provided between the upper leg and the lower leg.

In the biological condition monitoring system 100 of the above embodiment, between the load detection unit 1 and the A / D conversion unit 2, a signal amplification unit that amplifies the load signal from the load detection unit 1 and filtering that removes noise from the load signal. A part may be provided.

In the biological condition monitoring system 100 of the above embodiment, the display unit 5 is a simple device such as a printer that prints and outputs information indicating the biological condition, a lamp that displays the biological condition, or the like, in place of or in addition to the monitor. It may be provided with various visual display means. The notification unit 6 may include a vibration generation unit that performs notification by vibration in place of or in addition to the speaker.

As long as the features of the present invention are maintained, the present invention is not limited to the above-described embodiment, and other embodiments considered within the scope of the technical idea of the present invention are also included within the scope of the present invention. ..

According to the biological condition monitoring system of the present invention, the biological condition of a subject such as a respiratory condition and a heartbeat condition can be determined by using a system having a simple configuration and a small processing load. Therefore, it is possible to provide hospitals and long-term care facilities with a system that can obtain the status of inpatients, inpatients, and the like more inexpensively and quickly.

1 load detector, 1a, 1b, 1c, 1d load detector, 2 A / D conversion unit, 3 biological condition determination unit, 31 respiratory condition determination unit, 32 heartbeat condition determination unit, 4 storage unit, 5 display unit, 6 Notification unit, 7 input unit, 100 biological condition monitoring system, BD bed, BDS bed system, S subject

Claims (11)

A biological condition monitoring system that monitors the biological condition of a subject on the bed.
A first load detector provided under the bed or under the legs of the bed on one side in the width direction of the bed and detecting a load including a load component that is a load by the subject and vibrates according to the heartbeat of the subject.
A second load detector provided on the other side of the width direction of the bed under the bed or under the legs of the bed and detecting a load that is a load by the subject and includes a load component that vibrates according to the heartbeat of the subject.
A heartbeat state determination unit that obtains a difference between the load detected by the subject and the load detected by the second load detector by the first load detector and determines the heartbeat state of the subject from the difference. A biological condition monitoring system equipped with. The biological condition monitoring system according to claim 1, wherein the first load detector and the second load detector are arranged symmetrically with respect to an axis extending in the length direction of the bed at the center in the width direction of the bed. The second load detector is provided on one side in the length direction of the bed.
The load by the subject detected by the second load detector includes a load component that vibrates in response to the subject's respiration.
Further, a third load detection that is provided on the other side in the length direction of the bed under the bed or under the legs of the bed and that is a load by the subject and includes a load component that vibrates in response to the subject's respiration. With a vessel
A respiratory state determination unit that obtains a difference between the load detected by the subject and the load detected by the third load detector and determines the respiratory state of the subject from the difference. The biological condition monitoring system according to claim 1 or 2. The first load detector is provided on one side in the length direction of the bed.
The load by the subject detected by the first load detector includes a load component that vibrates in response to the subject's respiration.
The third load detector is provided on the other side of the bed in the width direction.
The load by the subject detected by the third load detector includes a load component that vibrates according to the subject's heartbeat.
Further, a load component provided under the bed or under the legs of the bed on one side in the width direction of the bed and the other side in the length direction of the bed, and which is a load by the subject and vibrates in response to the subject's breathing. It is equipped with a fourth load detector that detects a load including a load component that vibrates according to the subject's heartbeat.
The heartbeat state determination unit is the sum of the load by the subject detected by the first load detector, the load by the subject detected by the fourth load detector, and the subject detected by the second load detector. The difference between the load and the sum of the loads by the subject detected by the third load detector was obtained, and the heartbeat state of the subject was determined from the difference.
The respiratory state determination unit is the sum of the load by the subject detected by the first load detector, the load by the subject detected by the second load detector, and the subject detected by the third load detector. The biological condition monitoring system according to claim 3, wherein the difference between the load and the sum of the loads detected by the subject detected by the fourth load detector is obtained, and the respiratory state of the subject is determined from the difference. A biological condition monitoring system that monitors the respiratory condition of a subject on the bed.
A first load detector provided under the bed or under the legs of the bed on one side in the length direction of the bed and detecting a load that is a load by the subject and includes a load component that vibrates in response to the subject's respiration. ,
With a second load detector provided on the other side of the length direction of the bed under the bed or under the legs of the bed and detecting a load by the subject including a load component that vibrates in response to the subject's respiration. ,
A respiratory state determining unit that obtains a difference between the load detected by the subject and the load detected by the second load detector by the first load detector and determines the respiratory state of the subject from the difference. A biological condition monitoring system equipped with. Bed and
A bed system including the biological condition monitoring system according to any one of claims 1 to 5. It is a biological condition monitoring method that monitors the biological condition of the subject on the bed.
A first load detector provided on the bed or under the leg of the bed on one side in the width direction of the bed detects the load by the subject and includes the load component that vibrates according to the subject's heartbeat. When,
A second load detector provided on the other side of the width direction of the bed, which is provided on the bed or under the legs of the bed, detects the load by the subject and includes the load component which vibrates according to the subject's heartbeat. When,
A method including obtaining a difference between a load detected by the subject and a load detected by the second load detector by the first load detector and determining the heartbeat state of the subject from the difference. The biological condition monitoring method according to claim 7, wherein the first load detector and the second load detector are arranged symmetrically with respect to an axis extending in the length direction of the bed at the center in the width direction of the bed. The second load detector is provided on one side in the length direction of the bed.
The load by the subject detected by the second load detector includes a load component that vibrates in response to the subject's respiration.
A third load detector provided on the bed or under the leg of the bed on the other side in the length direction of the bed detects the load by the subject and includes the load component that vibrates in response to the subject's breathing. That and
A claim including obtaining a difference between the load detected by the subject and the load detected by the third load detector by the second load detector and determining the respiratory state of the subject from the difference. 7. The biological condition monitoring method according to 7. The first load detector is provided on one side in the length direction of the bed.
The load by the subject detected by the first load detector includes a load component that vibrates in response to the subject's respiration.
The third load detector is provided on the other side of the bed in the width direction.
The load by the subject detected by the third load detector includes a load component that vibrates according to the subject's heartbeat.
Further, by the fourth load detector provided under the bed or the leg of the bed on one side in the width direction of the bed and the other side in the length direction of the bed, the load by the subject is applied according to the breath of the subject. Includes detecting a load that includes a vibrating load component and a load component that vibrates in response to the subject's heartbeat.
The determination of the heartbeat state of the subject is detected by the sum of the load by the subject detected by the first load detector and the load by the subject detected by the fourth load detector, and the second load detector. The difference between the load by the subject and the sum of the loads by the subject detected by the third load detector is obtained, and the heartbeat state of the subject is determined from the difference.
Determining the respiratory state of the subject is detected by the sum of the load by the subject detected by the first load detector and the load by the subject detected by the second load detector, and the third load detector. The biological state according to claim 9, wherein the difference between the load by the subject and the sum of the loads by the subject detected by the fourth load detector is obtained, and the respiratory state of the subject is determined from the difference. Monitoring method. It is a biological condition monitoring method that monitors the respiratory condition of the subject on the bed.
A first load detector provided on the bed or under the legs of the bed on one side in the length direction of the bed detects the load by the subject and includes the load component that vibrates in response to the subject's breathing. That and
A second load detector provided on the bed or under the leg of the bed on the other side in the length direction of the bed detects the load by the subject and includes the load component that vibrates in response to the subject's breathing. That and
A biological state including obtaining the difference between the load detected by the subject and the load detected by the second load detector by the first load detector and determining the respiratory state of the subject from the difference. Monitoring method.

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