JP2014210137A - Body information measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a body information measuring device capable of more deeply detecting body information including a state of a sleep apnea syndrome, by acquiring more information by measuring breathing and heartbeat during sleeping in a non-contact manner.SOLUTION: A body information measuring device for acquiring body information on breathing and heartbeat of a detection target comprises: a base in a long shape; a plurality of radio wave radiation units which are disposed at different positions on the base and individually radiate radio waves having the same frequency band to the detection target; a radio wave reception unit for receiving a body information-including radio wave which is generated by a radio wave radiated from a radio wave radiation unit being reflected by the detection target and includes a detection target biological signal having periodicity; and a radio wave analysis unit for analyzing the radio wave received by the radio wave reception unit. The radio wave radiation units are positioned at a central region in the longitudinal direction of the base; where an abdomen radio wave radiation unit irradiates the abdomen of the detection target with a radio wave, and a chest radio wave radiation unit located apart from the abdomen radio wave radiation unit in the longitudinal direction of the base irradiates the chest of the detection target with a radio wave.

Description

  The present invention relates to a body information measuring apparatus that can acquire more information by measuring respiration and heart rate, and can detect body information deeper, including sudden changes in health and apnea syndrome.

  2. Description of the Related Art Conventionally, a body information measuring apparatus that measures body information such as heart rate and respiration rate of a subject such as a human or an animal is known. As a technique related to such a body information measuring device, for example, microwaves as electromagnetic waves are irradiated from a microwave transmission / reception sensor built in the bed toward the chest of the subject lying on the bed, and reflected electromagnetic waves, that is, reflected from the subject. It has been proposed to receive a microwave and detect a physical state such as a heart rate and a respiratory rate of a subject based on the received microwave (see, for example, Patent Document 1).

  In measurement by a Doppler microwave radar, an I / Q detection method is generally used in which two orthogonal signal components of an In-phase channel (I channel) and a Quadrature-phase channel (Q channel) are obtained as received signals. In this method, the received wave and the local wave are each divided into two, so that two combinations of the received wave and the local wave are prepared, and each combination is mixed using a mixer. Get a signal.

  At this time, if the body surface part oscillated by the pulse wave is orthogonal to the radar direction, the distance is short, and it is outside the so-called null detection point, the target signal is output to the radar. The heartbeat signal and the respiratory signal are best included. Therefore, when calculating the heart rate and the respiration rate, for example, FFT (Fast Fourier Transform) frequency analysis is performed, and the I channel signal and the Q channel signal are synthesized to improve the extraction accuracy, or null. Extract the channel signal away from the point, detect the regularity (constant frequency) of each signal, and detect the frequency of the target signal corresponding to the heart rate and respiration rate from a mixture of multiple input signals doing.

Patent Document 2 discloses a respiration measurement that irradiates a predetermined portion of a subject with a respiration measurement microwave and receives a reflected wave from the subject in order to measure heartbeats and respiration without contact and to make use of it for diagnosis. Transmission / reception means, and a heartbeat measurement transmission / reception means for receiving a reflected wave from a subject by irradiating a portion of the breathing measurement microwave that is different from the portion irradiated with the respiratory measurement microwave with a heartbeat measurement microwave having a frequency higher than that of the respiratory measurement microwave. And a detection means for detecting the phase of each received reflected wave, and a bandpass filter for filtering the respiratory signal component and the heartbeat signal component obtained by the phase detection in different frequency bands, and output of the bandpass filter Has been proposed for measuring the respiration rate and heart rate by obtaining the frequency at which the power is maximized from the above.
On the other hand, there have been reports on the use of air mats and fiber grating visual sensors for non-contact measurement of sleep apnea SAS (see Patent Documents 1 and 2).
The number of patients with sleep apnea syndrome in Japan (hereinafter abbreviated as SAS: Sleep Apnea Syndrome) is said to be several percent, and the number of patients is expected to increase in the future due to changes in lifestyle habits. SAS not only increases the probability of accidents during driving and work due to reduced concentration, but also causes the onset and worsening of heart disease and diabetes. Therefore, it is desired to detect and treat at an early stage. However, in order to diagnose SAS, a sleep polysomnography test (PSG: Polysomnography) is required, in which many contact sensors are worn on the body and measured overnight. The subject's normal sleep state is less restrictive. There was a demand to measure with this method. There are three main types of SAS: central sleep apnea syndrome, obstructive sleep apnea syndrome, and mixed sleep apnea syndrome with features of both, and each type of distinguishing diagnosis is important . Over 80% of patients are obstructive.

JP 2000-102515 A

JP 2008-99849 A

Examination of screening method for sleep apnea syndrome using air mat sensor, Akira Miyashita, Shunsuke Suzuki, Hiroyuki Yoshida, Mitsuhiro Honda, Masayuki Ohara, Japanese Society of Sleep Science, 1C-73, 2004.

Diagnosis of sleep apnea syndrome using a non-contact respiratory motion monitor, Yasuhiro Takemura, Hidetoshi Nakamura, Masato Nakajima, IEICE Transactions. D, Information and Systems J90-D (2), 567-577, 2007- 02-01

  However, the conventional physical information measuring device has a problem that it is impossible to measure apnea and hypopnea physical information with high accuracy. In particular, the physical condition could not be detected accurately, such as the detection of abnormal respiratory movements and heart rate increase during obstructive sleep apnea is impossible.

  Therefore, the object of the present invention is to obtain more information by measuring breathing and heartbeat during sleep without contact, and to detect body information deeper, including the state of sleep apnea syndrome. An object of the present invention is to provide a physical information measuring apparatus capable of performing the above.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have a problem in that the conventional measurement method and apparatus merely measure the vibration of bedding, and in order to obtain accurate information, breathing exercise If there is no direct measurement of body movement due to, the knowledge of apnea and hypopnea measurement accuracy will be limited, and further investigation will be made, and the radar output amplitude of the chest and abdomen will respond to changes in ventilation. It is thought that the information to judge the state of breathing more accurately can be obtained if the phenomenon that the time difference in the action accompanying breathing is used between the chest and the abdomen can be obtained accurately. In order to detect, it has been found that microwaves in the same frequency band may be irradiated to the chest and abdomen, and the present invention has been completed.
That is, the present invention provides the following inventions.
1. An elongated substrate;
A plurality of radio wave irradiation units arranged at different positions of the base body and radiating radio waves of the same frequency band toward the detection target;
A radio wave receiving unit that receives a radio wave containing physical information including a detection target biological signal having periodicity, the radio wave emitted from the radio wave irradiation unit being reflected by the detection target;
A radio wave analysis unit for analyzing the radio wave received by the radio wave reception unit,
A physical information measuring device for acquiring physical information related to detection target breathing and heartbeat,
The radio wave irradiation unit is located in the central region in the longitudinal direction of the substrate, and an abdominal radio wave irradiation unit that radiates radio waves to the abdomen to be detected;
The abdominal radio wave irradiation unit includes a chest radio wave irradiation unit that is installed apart from the abdomen in the longitudinal direction of the base and radiates radio waves to a chest to be detected.
2. The radio wave analysis unit
The abdominal reflected radio wave and the chest reflected radio wave are used to determine an output signal during normal breathing under a predetermined condition, and the determined output signal amplitude during normal breathing is recorded as a baseline, and an amplitude reduction rate from the baseline. 2. The physical information measuring device according to 1, wherein an apnea event or a hypopnea event in which an apnea state or a hypopnea state is suspected is determined based on the above.
3. The radio wave analysis unit
The phase of the abdominal reflected radio wave formed by the radio wave emitted from the abdominal radio wave irradiation unit being reflected by the abdomen of the detection target;
3. The physical information measuring apparatus according to claim 1, wherein obstructive apnea is determined from a phase of a chest reflected radio wave formed by reflecting a radio wave irradiated from the chest radio wave irradiating unit on the detection target chest.
4). The radio wave analysis unit
Whether or not the heart rate increases after a predetermined time has elapsed after the end of a hypopnea event or apnea event determined to be an apnea or hypopnea based on the amplitude decrease rate from the baseline. 3. The body information measuring device according to 2, wherein the heart rate data is recognized, and if there is an increase in the heart rate over a predetermined range, it is determined that the patient is in an apnea state or a hypopnea state. further,
A control unit for controlling the radio wave transmission unit and the radio wave reception unit;
The control unit
A first input signal is detected from an abdominal reflected radio wave formed by the radio wave emitted from the abdominal radio wave irradiation unit being reflected by the abdomen of the detection target,
A second input signal is detected from the chest reflected radio wave formed by the radio wave emitted from the chest radio wave irradiating part being reflected by the chest to be detected;
Generating a first I channel signal and a first Q channel signal orthogonal to each other from the first input signal;
Generating a second I channel signal and a second Q channel signal orthogonal to each other from the second input signal;
The radio wave analysis unit
Calculating the spectral densities of the first I channel signal, the first Q channel signal, the second I channel signal and the second Q channel signal, respectively;
From the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal, the prominent peaks of each spectral density at the same time within the main band of the detection target biological signal. Select the signal with the least number of
The physical information measuring device according to any one of claims 1 to 4, wherein the physical information measuring device functions to extract physical information about respiration and heartbeat from the selected signal.
6). 6. The radio wave analysis unit according to any one of 1 to 5, wherein the radio wave analysis unit detects a change in condition based on a change amount from a normal value obtained by measuring a respiratory rate and a heart rate in advance for each individual. Physical information measuring device.

  The physical information measuring device of the present invention can acquire more information by measuring respiration and heartbeat, and can detect physical information deeper including the state of apnea syndrome. It is also possible to provide a function as an alarm device for sudden changes in body condition due to abnormal respiratory rate and heart rate.

FIG. 1 is a perspective view showing one embodiment of the physical information measuring apparatus of the present invention. FIG. 2 is a schematic diagram schematically showing the internal structure of the microwave transmitting / receiving apparatus shown in FIG. It is a flowchart which shows the measuring method by the body information measuring apparatus which concerns on embodiment of this invention. It is a flowchart which shows in detail the amplitude change / phase difference detection step by the physical information measuring device which concerns on embodiment of this invention. FIG. 5 shows (a) the number of protruding peaks with one spectral density, (b) the number of protruding peaks with two spectral densities, (c) of the spectrum detected using the physical information measuring apparatus according to the embodiment of the present invention. And (d) a spectral density having four or more protruding peaks. It is a functional block diagram shown. It is a drawing substitute photograph which shows the example of a display of the display screen in embodiment which is a watching system which sounds an alarm at the time of the determination of apnea-hypopnea and respiratory rate heart rate sudden change. (A) Heart rate measurement result by Holter electrocardiograph, (b) Heart rate measurement result by physical information measuring device according to the present invention, (c) Body movement occurrence status at the same time is there. It is a graph which shows the measurement data of the phase difference of the chest and abdominal signal important in determining hypopnea and apnea. It is a graph which shows the measurement data of the amplitude important when judging central SAS and obstructive SAS from the presence or absence of respiratory effort.

Embodiments of the present invention will be described below with reference to the drawings.
The physical information measuring apparatus 1 of this embodiment shown in FIG.
An elongated substrate 10;
The radio wave irradiation unit 21 (see FIG. 2) that is arranged at different positions on the base body 10 and radiates radio waves in the same frequency band toward the person 90 to be detected, and the radio wave emitted from the radio wave irradiation unit is the person 90 Microwave transmission / reception devices 20 and 30 each including a radio wave reception unit 26 (see FIG. 2) that receives a radio wave containing physical information including a detection target biological signal having a periodicity that is reflected and generated;
And a radio wave analysis unit 40 that analyzes radio waves received by the radio wave reception unit, and obtains physical information related to a respiration and a heartbeat to be detected.

The base body 10 is in the form of a bed in the present embodiment, and is installed from the four corners of the lower surface of the bed 11 downward from the rectangular and flat bed 11 on which a person to be detected can sleep. And four rod-shaped leg portions 12.
The radio wave irradiation unit and the radio wave reception unit are arranged in the microwave transmission / reception devices 20 and 30, and the microwave transmission / reception devices 20 and 30 are embedded in the bed 11, respectively, and when the person 90 to be detected sleeps, The bed surface is flat so that there is no sense of incongruity.
The radio wave analysis unit 40 is installed below the bed so that signals can be transmitted reversibly via the microwave transmission / reception devices 20 and 30 and wiring (not shown). Applicable)

In the body information acquiring apparatus 1 of the present embodiment, the radio wave irradiation unit is located in the central region 15 in the longitudinal direction of the base 10 and the abdominal radio wave irradiation unit (in the microwave transmission / reception device 20) radiates radio waves to the human abdomen. And an abdominal radio wave irradiation unit that are spaced apart from each other in the longitudinal direction of the base and radiate radio waves to the chest of a person 90 (installed in the microwave transmitting / receiving device 20) It consists of. Specifically, the microwave transmission / reception apparatus having the radio wave irradiation unit and the radio wave reception unit is positioned in the longitudinal center region 15 of the base 10 so as to radiate radio waves to the human abdomen as configured as described above. The abdominal microwave transmitting / receiving device 20 and the abdominal microwave transmitting / receiving device 20 are spaced apart from each other in the longitudinal direction of the base 10, and the chest microwave transmitting / receiving device 30 irradiates the chest of a person 90 with radio waves. It consists of. As a result, the radio wave receiving unit is also located in the longitudinal center region 15 of the base body 10 in the same manner as the radio wave irradiation unit, and the abdominal radio wave receiving unit that receives radio waves irradiated to the human abdomen and the abdominal radio wave receiving unit are the base body. And a chest radio wave irradiation unit that receives radio waves applied to the human chest.
As shown in FIG. 1, the abdominal microwave transmission / reception device 20 (abdominal radio wave irradiation unit and abdominal radio wave reception unit) is disposed at substantially the center of the bed 11, and the microwave transmission / reception device 30 for the chest includes It arrange | positions in the position separated 10-30 cm in the longitudinal direction of the bed 11 rather than the microwave transmission / reception apparatus 20 for abdomen. Further, the microwave transmission / reception device 30 for the chest (chest radio wave irradiation unit and chest radio wave reception unit) is centered in the width direction so that the transmission / reception device is located at a point where the movement of the thorax becomes maximum when a person sleeps on the bed 11. It is arranged to be located on the left or right side from the line (spine position).
The abdominal microwave transmission / reception device 20 (abdominal radio wave irradiation unit and abdominal radio wave reception unit) is preferably arranged so as to be located on the back side of the human umbilicus when the person sleeps. It is preferable that the device 30 (the chest radio wave irradiation unit and the chest radio wave reception unit) is disposed as a longitudinal position of the base 10 so as to be positioned on the back side of the person's groove when the person sleeps.

The internal structure of the microwave transmitting / receiving apparatus will be described with reference to FIG. Here, the microwave transmission / reception device 20 for the abdomen will be described as an example, but the microwave transmission / reception device 30 for the chest is also configured similarly.
As shown in FIG.
The housing 2 is composed of two upper and lower lids 2a and 2b, and the radio wave irradiation unit 21 and the radio wave reception unit 26 are fixed to the lid 2a.
The radio wave irradiation unit 21 and the radio wave reception unit 26 are respectively connected to a control unit 25 that controls transmission and reception of radio waves via wiring (not shown), and the radio wave reception unit 26 is further wired to a radio wave analysis unit 40 (see FIG. (Not shown).

Although not specifically illustrated, a microwave transmitter and a microwave receiver will be briefly described. A microwave transmitter includes a transmitter that generates a microwave, a transmitter that transmits the generated microwave, and a transmitter. The microwave receiver includes an antenna that transmits the transmitted microwave to the outside, and the microwave receiver is an antenna that receives the microwave and a receiver that transfers the microwave received by the antenna to various devices for radio wave processing. It consists of.
Such microwave transmitters and microwave receivers include an impulse type and a Doppler type, and both can be used in the present invention, but a Doppler type is preferably used.
In addition, it is preferable that the microwave transmitter and the microwave receiver each have a configuration capable of measuring the dielectric constant, so that when a person gets up from the bed and moves away, the bed functions as a bed sensor. The presence or absence of a person on the top can be detected.
For measuring the dielectric constant, for example, a measuring instrument such as a network analyzer may be used, and the reflectance and transmittance are measured by irradiating a person with microwaves from an antenna (microwave transmitter). This makes it possible to detect whether or not a person exists.

The control unit 25 is for controlling the radio wave transmission unit 21 and the radio wave reception unit 26 to transmit a microwave and to receive a reflected microwave. The control unit 5 includes a ROM (read only memory) (not shown) in which programs and data for performing necessary processing are stored, a RAM (random access memory) (not shown) for temporarily storing signal data, A CPU (Central Processing Unit) (not shown) that performs predetermined processing stored in a ROM or the like.
Then, the control unit 25 detects the first input signal from the microwave reflected from the person 90 received by the radio wave receiving unit 26 (the microwave reflected from the abdomen), and detects the first input signal from the first input signal. A part of a program B, which will be described later, is stored so as to generate a Q channel signal, and a first complex signal forming unit 25a configured by a hardware circuit other than the above is provided. In addition, although the control part of an abdominal microwave transmission / reception apparatus is demonstrated here, the control part is similarly comprised also in the chest microwave transmission / reception apparatus.
Then, the difference between the first input signal (received wave) and the reference signal (local wave) of the local transmitter is extracted as an IF signal by a frequency mixer. At this time, two signals of a signal in phase with the first input signal and a signal delayed by 90 degrees are generated. Here, the in-phase component of the first input signal is the first I channel signal, and the quadrature component is the first Q channel signal. I channel signal, Q
Each channel signal becomes a real component and an imaginary component in the complex signal representation of the output signal. In the chest microwave transmission / reception apparatus, a similarly configured control unit functions in the same manner.

The first complex signal forming unit 25a obtains two orthogonal signal components of the above-described In-phase channel (I channel) and Quadrature-phase channel (Q channel) from the first input signal that is the reflected microwave. Although not particularly shown in the figure, a phase detection circuit for demodulating the first input signal as an IF signal (Intermediate Frequency) and a local transmitter are provided.
In addition, the physical information measuring device of the present embodiment may be provided with an amplification conversion device (not shown) that amplifies the received input signal and performs digital processing.
The amplification conversion device includes a direct current amplification unit and an A / D conversion unit (for example, the same as the device described in Japanese Patent No. 465228).
The direct current amplifier amplifies the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal. The A / D conversion unit converts the signal amplified by the DC amplification unit from an analog signal to a digital signal.

  For example, the amplifying / converting device includes, for example, a radio wave analysis unit 40 that samples a signal value sampled at a sampling frequency of 100 Hz from each of the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal. Output to. In other words, the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal are subjected to predetermined processing (amplification and amplification) by the DC amplification unit and the A / D conversion unit of the amplification conversion device. Conversion), and the signal subjected to the predetermined processing is output to the radio wave analysis unit.

The radio wave analysis unit 40 reflects the radio wave emitted from the abdominal radio wave irradiation unit 21 by the abdomen of the person 90 and is received by the abdominal radio wave reception unit 31, and the radio wave emitted from the chest radio wave irradiation unit 31. Is determined on the basis of a predetermined condition of the reflected signal from the chest of the person 90 and received by the chest radio wave receiver 32, and the output signal amplitude at the time of normal breath is determined as a baseline. , And based on the rate of amplitude decrease from the baseline, functions to determine an apnea event or hypopnea event in which an apnea or hypopnea is suspected.

The radio wave analysis unit 40 is irradiated from the chest radio wave irradiation unit 31 and the phase of the abdominal reflection radio wave received by the abdominal radio wave reception unit 31 after the radio wave irradiated from the abdominal radio wave irradiation unit 21 is reflected by the abdomen of the person 90. The phase difference is detected by comparing the phase of the radio wave reflected by the chest of the person 90 and received by the chest radio wave receiver 32, and if the phase difference exceeds a predetermined threshold, breathing is performed. Works to detect situational anomalies.
When it is detected as abnormal, it is connected to an alarm device (not shown) via wiring so that other people can be notified.

Hereinafter, the radio wave analysis unit 40 will be described in detail.
The radio wave analysis unit 40 includes a computer. Specifically, although not particularly illustrated, the radio wave analysis unit 40 is a recording medium such as a hard disk in which a program for analyzing microwaves having physical information received by the radio wave reception unit is stored, data, A central processing unit (CPU) that temporarily stores a program, performs processing of received microwaves according to the program, obtains information according to a predetermined procedure, and outputs it to the outside in a predetermined case And a display unit such as a monitor for displaying the calculated physical information. These hardware-related configurations can be configured in the same manner as a conventionally known computer.

In the apparatus 1 of the present embodiment, the radio wave analysis unit 40 records the following program (hereinafter referred to as “program A” when referring to this program) in order to make the computer function as an apparatus that performs predetermined radio wave analysis. Stored on media.
That is, the program A determines an output signal during normal breathing under a predetermined condition for the abdominal reflected radio wave and the chest reflected radio wave, and records the determined output signal amplitude during normal breathing as a baseline. Based on the rate of decrease in amplitude from the baseline, it is configured to achieve the function of determining apnea or hypopnea events in which apnea and hypopnea are suspected. The radio wave irradiated from 21 is reflected by the abdomen of the person 90 and received by the abdominal radio wave receiver 31, and the radio wave emitted from the chest radio wave irradiator 31 is reflected by the chest of the person 90. An abnormality detection function that detects an abnormality in the respiratory condition from the phase of the chest radio wave received by the chest radio wave receiving unit 32, and other people can be notified if it is detected as abnormal. ; And a transmission function for operating the sea urchin alarm device.
For this reason, the radio wave analysis unit 40 provided with the program A is configured to exhibit the detection function, the abnormality detection function, and the transmission function, and simply detecting the respiration rate thereby. In addition, abnormal breathing conditions such as apnea syndrome can be detected and notified to an external person.

The radio wave emitted from the abdominal radio wave irradiation unit 21 is reflected by the abdomen of the person 90 and the first input signal is detected from the abdominal radio wave reception wave received by the abdominal radio wave reception unit 31. Is detected from the chest reflected radio wave reflected by the chest of the person 90 and received by the chest radio wave receiving unit 32, and the first I channel signal and the first Q channel signal orthogonal to each other from the first input signal are detected. And generating a second I channel signal and a second Q channel signal orthogonal to each other from the second input signal,
The radio wave analysis unit 40 calculates the spectral densities of the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal, respectively, and the first I channel signal and the first Q channel signal are calculated. From the second I-channel signal and the second Q-channel signal, a signal having the smallest number of prominent peaks of each spectral density at the same time within the main band of the detection target biological signal is selected. It functions to extract physical information about the heartbeat.

For this reason, the control unit 25 and the radio wave analysis unit 40 store the following program (hereinafter referred to as “program B” in the case of “program B”) in the recording medium so that the computer performs the above-described functions. Has been.
That is, the program B is
A first input signal detection function for detecting a first input signal from an abdomen reflected radio wave reflected by the abdomen of the person 90 and received by the abdominal radio wave receiver 31;
A second input signal detection function for detecting a second input signal from the chest reflected radio wave received by the chest radio wave receiving unit 32 after the radio wave emitted from the chest radio wave irradiating unit 22 is reflected by the chest of the person 90;
A first signal generating function for generating a first I channel signal and a first Q channel signal orthogonal to each other from the first input signal;
A second signal generation function for generating a second I channel signal and a second Q channel signal orthogonal to each other from the second input signal;
A spectral density calculation function for calculating a spectral density of each of the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal;
A signal having the smallest number of peaks of each spectral density at the same time within the main band of the detection target biological signal from the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal. A selection function to select
And an extraction function for extracting body information about respiration and heartbeat from the selected signal.
In the program B, the first input signal detection function, the second input signal detection function, the first signal generation function, and the second signal generation function are stored in the control unit 5. The spectrum density calculation function, the selection function, and the extraction function are stored in the radio wave analysis unit 40.
Therefore, the radio wave analysis unit 40 includes the first input signal detection function, the second input signal detection function, the first signal generation function, the second signal generation function, the spectral density calculation function, and the It is comprised so that a selection function and the said extraction function may be exhibited, and, thereby, the information of respiration and a heartbeat can be grasped | ascertained correctly.

In the present embodiment, the part of the program B included in the radio wave analysis unit 40 is a spectrum density calculation function, a selection function, and an extraction function.
In order to realize these functions, the radio wave analysis unit 40 functions as a frequency selection unit, an amplitude compression unit, a frequency conversion unit, a peak number selection unit, and a signal analysis unit according to the program B. ing.

The functions as a frequency selection unit, an amplitude compression unit, and a frequency conversion unit are functions for realizing a spectral density calculation function, respectively.
The function as the frequency selection unit makes it easy to detect a biological signal by reducing the signal intensity other than the main band of the heartbeat signal (biological signal) or the respiratory signal (biological signal) with respect to the signal from the amplification conversion device. The processing for realizing the above is realized. And the function as a frequency selection part is performed by performing what is called filtering (band pass filtering) (for example, refer patent 40405394 gazette). The program for this can be configured using a known method without any particular limitation. For example, 0.5 [Hz] can be set in advance as the minimum heartbeat frequency and 3.0 [Hz] can be set in the maximum heartbeat frequency as the heartbeat passband. Moreover, 0.015 [Hz] can be preset for the minimum frequency for respiration, and 0.5 [Hz] can be set for the maximum frequency for respiration.

The function as an amplitude compression unit is to facilitate extraction of a heartbeat signal and a respiratory signal from a first input signal (reflected wave) and a second input signal (reflected wave) in which a plurality of biological signals are mixed. It is preferable to provide an AGC (Automatic Gain Control) circuit in the radio wave analysis unit 40 in order to provide only the amplitude of each wave of an input signal whose intensity exceeds a predetermined threshold value according to a heartbeat signal or a respiratory signal. Is a functional means for performing processing for maintaining the amplitude of the wave of the intensity within the threshold value as it is. For example, in the case of a heartbeat signal, the threshold value is set to ± 0.03 [V] when the magnitude of amplitude is displayed in voltage.
As the compression processing by the AGC circuit, the waveform is reduced by multiplying the peak waveform or valley waveform by a coefficient obtained by dividing the threshold value by the maximum value of the peak waveform of the input signal or the minimum value of the valley waveform of the wave.

  The function as the frequency conversion unit is, for example, a well-known fast Fourier transform (FFT: Fast Fourier Transform) described in Japanese Patent Application Laid-Open No. 2001-257611, Japanese Patent Application Laid-Open No. 2006-258786, or the like. Transform) is a functional means for calculating the spectral density. Note that FFT is an algorithm for calculating a discrete Fourier transform (DFT) at high speed on a computer.

The function as the peak number selection unit is a function for realizing the selection function, and the waveform of each spectral density of the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal at the same time. By selecting a signal that minimizes the number of prominent peaks in the main band of the heart rate signal or respiratory signal. The trace of the waveform of the spectral density as shown in FIG. 5 may be displayed on a display unit (not shown) of the radio wave analysis unit, or may be stored in a recording medium without being particularly displayed.
Here, “the number of prominent peaks” is the same spectral density distribution diagram, after setting the maximum output value within a predetermined frequency step size to “peak”, the peaks are arranged in descending order of the peak value. Sometimes, for a predetermined numerical value α (for example, 3.0), if there is a minimum integer n in which the n-th peak is α times larger than the n + 1-th peak, that n is expressed as a “protruding peak”. Number of ". When n exceeds a certain integer (for example, 5), the number of peaks is 5.

  In other words, the smaller the number of peaks with prominent spectral density, the less the disturbance due to body motion, and the generation of harmonics and intermodulation waves, and as a result, the detection target biological signal can be detected with high accuracy. By analyzing the detection target biological signal based on the signal having the spectral density that minimizes the physical information, it is possible to extract highly accurate body information.

  The function as the signal analysis unit is for realizing the extraction function. For example, a known signal described in paragraphs [0043] to [0048] of Japanese Patent Application Laid-Open No. 2010-178933 is performed and the selected signal is selected. By calculating the heart rate and the respiration rate from the spectral density, body information relating to respiration and heart rate can be acquired.

(how to use)
The body information measuring apparatus 1 of this embodiment is used as follows.
First, the body information measuring apparatus 1 is turned on, and a person uses the bed in a state where microwave irradiation and reception are possible. Preferably, a person sleeps on a bed, but breathing and heart rate information can be detected if there is a person on the bed.
In this way, if a person sleeps on the bed with the apparatus turned on, microwaves are irradiated from the abdominal radio wave irradiation unit and the chest radio wave irradiation unit and the microwaves are applied to the sleeping person.
The microwave hitting the person is reflected in a radio wave state different from that at the time of irradiation due to the physical movement of the person, and the reflected microwave is received by the abdominal radio wave receiving unit and the chest radio wave receiving unit.
The received microwave is transferred to the radio wave analysis device 40, and the microwave information is analyzed by the radio wave analysis device including the program A and the program B to obtain information on predetermined respiration and pulse.
Here, the radio waves irradiated from the abdominal radio wave irradiation unit and the chest radio wave irradiation unit are radio waves in the same frequency band. Specifically, it is preferable to use a material having a frequency band of 24.05 to 24.25 Hz for both. However, shifting the frequency band to avoid interference is included in the “same frequency band” in the present invention. That is, in the present invention, the “same frequency band” means that a plurality of frequency bands are not used depending on the measurement purpose, such as a respiration frequency band and a heartbeat frequency band.
The analysis method will be described below together with the operations of the programs A and B.
A measurement method in the sleeping state will be described.

(Measuring method)
In order to measure physical information such as breathing and heartbeat by the physical information measuring apparatus 1 of the present embodiment, first, as shown in FIG. 3, an irradiation step of irradiating a microwave toward a person to be detected, and hitting the human body A reception step of receiving the reflected microwave, a complex signal formation step of forming a complex signal by the control unit 25, and a microwave received by the radio wave analysis unit 40 are determined by determining an output signal during normal breathing. The output signal amplitude during normal breathing is recorded as a baseline, and an amplitude change / phase difference detection step (apnea) is a step for detecting abnormalities in the respiratory condition based on the amplitude reduction rate and phase difference from the baseline. This can be performed by performing a hypopnea determination step) and an analysis step (respiration rate / heart rate detection step) of analyzing the microwave and acquiring physical information.
Hereinafter, each step which comprises the measuring method which analyzes the received microwave and measures physical information is demonstrated.

The irradiation step irradiates the microwave 90 in the above-mentioned frequency band with a predetermined intensity (preferably an antenna power of 10 mW or less) toward the person 90 who sleeps on the base from the microwave transmission unit disposed in the microwave transmission / reception devices 20 and 30. To do.
In the receiving step, the microwave transmitting / receiving device 20 receives the reflected microwave (first input signal) of the abdomen and the reflected microwave (second input signal) of the chest, which are reflected when the microwave transmitted from the microwave transmitting device hits the person 90. , 30 is received by the microwave receiver.

In the complex signal forming step, the microwaves received by the microwave receiving devices of the abdomen and chest are converted by the complex signal forming unit 25 from the first input signal and the first Q channel signal orthogonal to each other from the first input signal. Is generated. In the second complex signal forming step (S04), the second complex signal forming unit 10 generates a second I channel signal and a second Q channel signal that are orthogonal to each other from the second input signal.
Then, the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal created here are each amplified to a predetermined magnitude and A / D converted by the amplification converter 6. The result is output to the radio wave analysis unit 40.

Next, the analysis step will be described.
As shown in FIG. 3, the analysis step can be performed by executing a frequency selection step, an amplitude compression step, a frequency conversion step, a peak number selection step, and a signal analysis step.
In the frequency selection step, signal strengths other than the main band of the heartbeat signal or the respiratory signal are reduced with respect to the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal. This is processed by a frequency selection unit in the computer 7.

  In the amplitude compression step, the amplitude compression unit 15 determines in advance the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal according to the heartbeat signal and the respiratory signal. Only the amplitudes of the individual waves of the input signal having the intensity exceeding the threshold value are compressed, while the amplitudes of the waves having the intensity within the threshold value are left as they are.

  Since the output of the respiratory signal is about 100 times that of the heartbeat signal, the body motion signal may be removed first in the amplitude compression step after the reception step, and then the frequency selection step may be performed.

  In the frequency conversion step, the frequency conversion unit calculates the spectral densities of the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal.

  In the peak number selection step, the peak number selection unit 17 calculates the heart rate from the distribution of the spectral densities of the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal at the same time. A signal is selected that minimizes the number of prominent peaks in the main band of the signal or respiratory signal. For example, when the spectral density as shown in FIGS. 5A to 5D is obtained, one signal shown in FIG. 5A having the smallest number of protruding peaks is selected.

  In the signal analysis step, the signal analysis unit calculates the heart rate and the respiration rate based on the signal having the selected spectral density.

  According to the physical information measuring apparatus 1 and the physical information measuring method, the spectral densities of the four signals of the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal are compared. Then, a signal having a spectral density that minimizes the number of protruding peaks can be selected, and analysis can be performed based on this signal.

  Therefore, even in a measurement environment where the radio wave transmitter / receiver's opposition to the person, distance, etc. change from moment to moment due to human body movements, the heart rate and respiratory rate can be accurately extracted by reducing the effects of changes. Can do.

  Here, “the distribution shape of the spectral density is the best” means that even if the input signal has the same spectral density with the number of protruding peaks, the peak of the spectral density is steeper or the maximum peak value is the second largest. This means a distribution state in which there is a peak having a larger difference between peaks compared to the peak value.

  In the present invention, since the input signal having the best spectral density distribution shape includes the detection target biological signal with higher accuracy, the spectral density distribution is based on the evaluation index corresponding to the number of protruding peaks. The input signal having the best shape is selected and the respiratory rate and heart rate are detected with high accuracy from the output signal of the microwave transmitting / receiving device 20. Therefore, the detection of the apnea / hypopnea state is performed by analyzing the complex signal generated by the elementary signal forming step based on the output signal from the microwave transmitting / receiving apparatus 20.

The apnea / hypopnea detection step, which is a step (amplitude change / phase difference detection step) for detecting an abnormality in the respiratory condition, will be described below.
As shown in FIG. 3, the apnea / hypopnea detection step using the microwave transmission / reception device 20 includes a setting step of a stable average respiratory heart amplitude value (baseline), a setting step of a stable average heart rate, a respiratory amplitude. Reduction rate determination step, heart rate increase event determination step, respiratory strange motion determination (phase determination) step, and stable period, hypopnea event, apnea event recording step.
Sleep apnea syndrome is a disease in which the number of breathing stops or hypopneas during sleep exceeds the diagnostic criteria. Apnea is that the airflow in the mouth and nose stops for 10 seconds or more, and hypopnea is that the ventilation decreases by 50% or more for 10 seconds or more. The apnea hypopnea index (AHI) representing the severity is the total number of apneas and hypopneas per hour of sleep. AHI is diagnosed as 5-15 times mild, AHI 15-30 times moderate, and AHI more than 30 times severe.
In order to grasp such an apnea-hypopnea state during sleep, an apnea event and a hypopnea event are monitored as shown in FIG.
Therefore, as shown in FIG. 4, as a step of setting the stable average respiratory heart amplitude value (baseline), a normal state that is neither apnea nor hypopnea in the state of breathing during sleep is measured and set in advance. This is called the stable period. Compared to this stable period, the period of hypopnea is the period of the hypopnea event, and the apnea state is the period of the apnea event (any state is hypopnea apnea) Will be described later).
Prior to monitoring the above-described event, the respiratory average amplitude value in the stable state of the output signal in the microwave transmitting / receiving apparatus is set as the stable baseline, respectively for the chest and abdomen. In addition, the average heart rate in the stable state is set by the above-described method, the respiratory state during sleep is determined based on the information, the abnormal state is detected, and whether or not the abnormal state is hypopnea. Determine if you are breathing.
In order to achieve these functions, the radio wave analysis unit 40 determines an output signal during normal breathing under predetermined conditions for the abdomen reflected radio wave and the chest reflected radio wave, and determines the determined output signal amplitude during normal breathing. Record as a baseline, determine an apnea event or hypopnea event suspected of apnea and hypopnea based on the amplitude reduction rate from the baseline, and further, the abdominal reflected radio wave and the chest reflected radio wave A means for determining obstructive apnea from the phase difference is provided, and a program for functioning as such means is stored.
In addition, the radio wave analysis unit 40 increases the heart rate after a lapse of a certain time after the end of a hypopnea event or an apnea event determined to be an apnea or hypopnea based on the amplitude decrease rate from the baseline. It is configured to recognize the heart rate data to be acquired or not, and when there is an increase in the heart rate over a predetermined range, it is determined to be an apnea state or a hypopnea state. A program for functioning as a means is stored. Specifically, as shown in FIG. 4, a setting step for setting an average heart rate in a stable period is performed to set a heart rate in a stable period, and a determination step for a heart rate increase event is performed to perform hypopnea / apnea described later. An apnea state or a hypopnea state is determined by checking whether or not the heart rate has increased after the occurrence of the event.

More specifically, as shown in FIG. 6, the complex signal obtained by the complex signal formation step is acquired for each of the four channel outputs of I and Q in the abdomen and chest, and the amplitude that can be determined as the stable respiratory period. The value (graph in the figure, the amplitude of the stable breathing period is called the baseline) is extracted and used as a reference.
Extraction of the amplitude value that can be determined as the stable breathing period is preferably a time width of 120 seconds or more, and the amplitude is the amplitude threshold value of the respiratory signal for body movement determination (the amplitude width is 0.5 V for the I channel and 0.5 V for the Q channel). Smaller than that.
The amplitude value that can be determined as the stable breathing period can be updated, and if a stable amplitude of more than the stable time width continues for each channel, if it can be recognized as a different standard, update it as a new standard. Save to a recording medium.
The stable breathing period is a period of time longer than the stable period time period in which there is no body movement and neither the low breathing period nor the apnea period, and the average amplitude value of the stable period time width in that period is referred to as a stable respiratory average amplitude value.
Furthermore, the heart rate obtained by the aforementioned extraction function in the stable breathing period is stored as the stable period average heart rate.

And the presence or absence of a hypopnea event and an apnea event is detected by the determination step of the reduction ratio of the respiratory amplitude. A hypopnea event is a case where a hypopnea state in which the amount of ventilation (estimated from the output intensity) is lower than that in a normal state continues for a predetermined period, and an apnea state is a case where a state without breathing continues for a predetermined period.
In the hypopnea event, for example, the larger signal channel line (chest I in FIG. 5) of the two stable respiratory mean amplitude values A11 and A12 of the chest is selected from two every 5 seconds, and the signal channel line is selected. When the amplitude width of the signal channel is in the range of, for example, 50 to 20% of the average amplitude value of the stable respiratory period (this value is adjusted based on the relationship between the ventilation volume and the radar amplitude value), the time is 10 seconds. In this case, it is a chest hypopnea event.
The apnea event is in the range of, for example, 19 to 0% of the amplitude from the average value of the stable respiratory period for the signal channel line of interest (this value is also adjusted based on the relationship between the ventilation volume and the radar amplitude value). If the time is 10 seconds or more, it is a chest apnea event.
Similarly, for the abdomen, the larger signal channel line (abdominal part Q in FIG. 5) of the two stable respiratory average amplitude values A21 and A22 is selected from two every 5 seconds, and the signal channel line is selected. In the case where the amplitude is in the range of 50 to 20% from the stable respiratory period average amplitude value and the time is 10 seconds or more, an abdominal hypopnea event is determined.
Further, when the signal channel line of interest is 10 seconds or more in which the amplitude is in the range of 19 to 0% from the average value of the stable respiratory period, it is determined as an abdominal apnea event.
A hypopnea event occurs when a hypopnea event occurs on one side of the abdomen or chest, and an apnea event occurs when an apnea event occurs. If there is a hypopnea event in either the chest or abdomen and there is an apnea event on the other side, an apnea event occurs.

If hypopnea events and apnea events occur in succession, if the time ratio of apnea events is greater than or equal to “minimum percentage of the apnea duration (usually 50%)” Be apnea and display a red band for the length of time to call attention. Here, the “red band” is a display means that means a dangerous state.
If the time ratio of a hypopnea event is equal to or greater than the “minimum ratio% (typically 50%) shown during the duration of hypopnea”, the entire period is set to a hypopnea state, and a yellow belt is displayed for the length of that time. Display and call attention. Here, the “yellow belt” is a display means that means a somewhat dangerous state. When a display device is provided, these red band and yellow band are represented on the display device.

On the other hand, the phase difference between the chest respiratory signal and the abdominal respiratory signal is confirmed by comparing them at the same time as shown in FIG.
It is known that hypopnea and apnea are central and obstructive. However, as shown in FIG. 9, in the case of centrality, there is almost no amplitude. If the amplitude decreases, it can often be determined that the patient is in an apnea condition. However, in the case of obstruction, the airflow in the mouth and nose is stopped as shown in FIG. 8, but the chest and abdomen should continue to breathe. As a result of the respiratory effort described above, since the chest and abdomen continue to vibrate, it is difficult to determine whether the patient is hypopnea or apnea by simply reducing the amplitude from the baseline. Therefore, obstructive apnea needs to be determined using the phase difference.
In such an amplitude change / phase difference detection step, the complex signal generated by the complex signal formation step is transferred to the radio wave analysis unit 40, and the amplitude change / level is detected for detecting the phase of the microwave received by the transferred complex signal. The phase difference detection step is performed by the radio wave analysis unit 40.
The amplitude change / phase difference detection step can be performed by executing the radio wave analysis unit 40, and the radio wave emitted from the abdominal radio wave irradiation unit 21 is reflected by the abdomen of the person 90 and received by the abdominal radio wave reception unit 31. The phase of the reflected abdominal radio wave is compared with the phase of the reflected chest radio wave received by the chest radio wave receiving unit 32 after the radio wave emitted from the chest radio wave radiating unit 31 is reflected by the chest of the person 90. This is done by performing a step of detecting the phase reversal of the respiratory motion of the chest and abdomen.
Specifically, after performing the above-described step of detecting the phase difference by comparing the complex signal obtained in the complex signal forming step, the primary phase is obtained by looking at the phase as shown in FIG. In addition to detecting hypopnea events and apnea events, and detecting the presence or absence of heart rate information and reflecting the results, as a step of determining the respiratory abnormal movement (phase determination), look at the phase difference and check the chest and abdomen. It is determined whether or not there is an abnormal respiratory motion that is a phase reversal state of the respiratory motion, and further, the abnormality of the respiratory condition is detected by incorporating this result into the determination. In addition, if necessary, a step of recording a stable period, a hypopnea event, and an apnea event may be performed in the case of a hypopnea event and an apnea event, a step of recording an event occurrence state on a storage medium according to a predetermined standard. .
The details will be described below.

In this step, the complex signal obtained by the complex signal forming step as shown in FIG. 6 is acquired for each of the four channel outputs of I and Q in the abdomen and chest, respectively, and as shown in FIGS. The phase is detected by comparing the I channel of the chest and the Q channels of the chest or Q channels with the same time axis and amplitude axis.
For example, the cross-correlation function between the chest respiratory signal and the abdominal respiratory signal for about 40 seconds is calculated every second, and the deviation of the cross-correlation function from the Y-axis (the deviation of the position after the first peak peak or valley appears) is 90. If it is more than ° (1/4 or more of the time required between the 1st peak and the 2nd peak), it is considered as a breathing weird movement, and the above-mentioned hypopnea state is upgraded to an obstructive apnea state, and it becomes a red belt.
Even if the phase difference (peak shift) between the chest respiratory signal and the abdominal respiratory signal is generated, if the relevant period is not in a low respiratory state, the obstructive apnea state is not determined and the stable period is determined.

In the above processing, the setting for presence or absence of heart rate increase determination may be added as a determination step for the heart rate increase event. In this case, the following heart rate increase verification processing is retroactively performed.
Thus, apnea and hypopnea displays are typically written with a time delay of about 30 seconds to 1 minute.
The heart rate increase verification process associates with the heart rate increase event from the end of the apnea event or hypopnea event, and the heart rate increases by 10% or more compared to the average heart rate in the stable period by the extraction step. However, if the time is 5 seconds or more, it is a rise in heart rate induced from the results of hypopnea and apnea events, and is recorded as a heart rate rise event. When this heart rate increase event occurs, the amplitude is 80% to 50% from the average value of the stable breathing period in the time zone in which the heart rate increase event is associated (this value is also based on the relationship between the ventilation volume and the radar amplitude value). If the time within the range of “adjusted” is 10 seconds or more, the amplitude value is larger than the hypopnea determination condition, but a hypopnea event occurs.

(Condition parameters for apnea / hypopnea determination)
Each parameter for determining apnea or hypopnea can be as follows.
Amplitude range of normal baseline (Amplitude is 0.5V or less, amplitude measured in advance and not set to apnea or hypopnea)
The minimum duration of an apnea event (if it continues to be considered apnea for 10 seconds),
Amplitude ratio with apnea normal baseline (20% line from normal baseline)
Minimum rate (50%) shown during the duration of apnea
Here, the “minimum ratio” refers to the minimum ratio of the entire apnea period for determining that the entire period is apnea when apnea and hypopnea occur continuously.
Minimum duration of hypopnea event (10 seconds)
Ratio between the amplitude of hypopnea and normal baseline amplitude (50% or less)
Minimum rate (50%) indicated during duration of hypopnea
Time between adjacent events combined (If within 5 seconds, combine them into one event)
Association with heart rate rise event (within 30 seconds after the event)
Phase difference condition for determining a hypopnea event as an obstructive apnea event Phase difference (90 degrees or more)
Normal baseline setting stable period (120 seconds)
Amplitude threshold of respiratory signal when it is determined that there is body movement (0.50V for both abdomen and chest)

(Step to activate the alarm device)
Further, based on the information on the respiratory rate and the heart rate, it is possible to set so that an alarm is sounded especially when the condition suddenly changes.
Conditions for alarm ringing when conditions change suddenly are set according to the monitoring purpose of each facility. In addition, breathing rate and heart rate vary from person to person in normal times, and it is possible to set an abnormal range according to the value of each person. Regardless of necessity, it is necessary to avoid an alarm sounding more than necessary. In order to ensure such a function, the radio wave analysis unit 40 detects a change in condition based on a change amount from a normal value that is measured and set in advance for each person's breathing rate and heart rate. It is configured.
Therefore, it is preferable to set the individual characteristics as follows in a non-contact monitoring apparatus using a radar.
・ When the heart rate is lower than the lower limit reference value A (for example, 50 times / min of the pulse reduction reference) continues for the reference time AT (for example, 60 seconds). When the state of being higher than (for example, 40 times / minute) continues for the reference time BT (for example, 60 seconds). The state for which the respiratory rate is equal to or lower than the lower limit reference value C (for example, 5 times / minute) is the reference time CT (for example, 60 seconds). ) When continuing ・ When the breathing rate is higher than the normal average value PR over the reference value D (for example, 7 times / minute) for the reference time DT (for example, 60 seconds), the system's external constant heart rate lower limit reference Value A (initial value 50), heart rate reference time AT (initial value 60)
Heart rate rise reference value B (initial value 40), heart rate reference time BT (initial value 60)
Respiration lower limit reference value C (initial value 5), respiration reference time CT (initial value 60)
Respiration rise reference value D (initial value 7), respiration reference time DT (initial value 60)
Personally set external constant normal heart rate average PH, normal respiratory average PR
This personal setting information is registered from the registration screen for each measurer (bedside device) from the PC screen. As shown in FIG. 6, it is displayed somewhere on the measurement result display screen.
In order to determine the alarm ringing, it is preferable that there is a bed sensor (such as weight detection by a piezoelectric element or a determination method based on a reflected wave signal intensity of a Doppler radar). An alarm corresponding to the change in breathing rate and heart rate is sounded only while the person being measured is on the bed, so that the breathing and cardiac arrest alarms are not accidentally sounded when there is no subject on the bed. It is necessary to.

The radio wave analysis unit 40 may further include a best shape selection unit.
The best shape selection unit protrudes when the number of peaks with protruding spectral density is the same between the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal. The first evaluation index, the second evaluation index, or the third evaluation index applied according to the number of peaks obtained is calculated, and the shape of the spectral density distribution is further best from signals having the same number of protruding peaks. Select a signal with a spectral density of

  Here, the first evaluation index selects a signal having the best shape of the spectral density distribution from a plurality of signals having a number of peaks having a prominent spectral density within a range of 0 to 1, for example, The power amount of one protruding peak is set to approach zero (the shape of the spectral density distribution is the best) as it approaches the value of the total power amount of the entire main band of the heartbeat signal or respiratory signal. The second evaluation index selects a signal having the best shape of the spectral density distribution from a plurality of signals having two spectral peak peaks in the range of 1 to 2, for example, the highest peak. The smaller the peak value that protrudes second than the peak value, the closer the value is to 1 (the shape of the spectral density distribution is the best).

  The third evaluation index selects a signal having the best shape of the spectral density distribution from a plurality of signals having a number of peaks with prominent spectral densities in the range of 2 to 4, for example, the most prominent. The smaller the peak value that protrudes second from the peak value, and the smaller the peak value that protrudes third from the most prominent peak value, the closer to 2 (the spectral density distribution). (The shape is the best). Then, the best shape selection unit 22 selects a signal having a spectral density distribution that minimizes the evaluation index.

  Note that the fourth evaluation is calculated by comparing the magnitudes of the protruding peak values as described above with respect to a signal in which the number of peaks with protruding spectral density is 4 or more, or set to a predetermined value in advance. An index may be further provided. Then, the best shape selection unit may select a signal having a spectral density distribution that minimizes the evaluation index among the first evaluation index, the second evaluation index, the third evaluation index, and the fourth evaluation index. Hereinafter, a case where the computer has a fourth evaluation index will be described.

  At this time, when there are a plurality of signals having a spectral density that minimizes the number of peaks and minimizes the evaluation index, the best shape selection unit 22 defines a priority order for selecting one signal. That is, the best shape selection unit 22 selects one signal in the order of the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal. For example, when the signals having the spectral density with the smallest number of peaks and the smallest evaluation index are the first Q channel signal and the second Q channel signal, the first Q channel signal is selected.

  When using a physical information measuring device, it is preferable to perform the best shape selection step after the peak number selection step.

  In the best shape selection step, the best shape selection unit calculates the first evaluation index, the second evaluation index, the third evaluation index, or the fourth evaluation index according to the number of peaks in which the spectral density is prominent. The signal having the best spectral density distribution shape is selected from among the signals having the same number.

  Here, the first evaluation index is, for example, V = 1− (P1 / Pt) (P1 is a peak value, Pt is the entire main band of a heartbeat signal or a respiratory signal with respect to the spectral density shown in FIG. (Total power). That is, the evaluation index V approaches 0 as P1 approaches Pt (there is no other peak in the corresponding band and one projecting peak has a steeper shape).

  The second evaluation index is, for example, V = 1 + (P2 / P1) (P1 is the larger peak value of the two protruding peaks, and P2 is the smaller of the spectral densities shown in FIG. 5B. Peak value). That is, the evaluation index V approaches 1 as the difference between the two peak values increases.

  The third evaluation index is, for example, V = 2 + (P2 / P1) + (P3 / P1) (P1 is the largest peak value among the three protruding peaks with respect to the spectral density shown in FIG. 5C. , P2 is represented by the second largest peak value, and P3 is represented by the third largest peak value). That is, the evaluation index V approaches 2 as the most prominent peak value is larger than the other peak values.

The fourth evaluation index is for a spectral density having four or more protruding peaks as in the spectral density shown in FIG. 5D, and is set to a constant value of 5.
Then, each evaluation index V corresponding to the number of peaks with prominent spectral densities is calculated, and a signal having the smallest value of V is sent to the signal analysis step (S09).

  At this time, when there are a plurality of signals having a spectral density that minimizes the number of peaks and minimizes the evaluation index, the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal The first signal is selected in the following order.

  According to the physical information measuring device 20 and the physical information measuring method, even with input signals having the same spectral density with the number of protruding peaks, the spectral density distribution shape is better (a steeper peak, or between other peak values). Input signal can be selected, and as a result, a signal including a more suitable heart rate signal and respiration signal can be selected, and heart rate and respiration rate can be extracted with higher accuracy. be able to.

Furthermore, the body information measuring apparatus 1 according to the present embodiment may include a drive unit that moves the antenna in a desired direction.
Although not particularly illustrated, the drive unit preferably includes a drive mechanism unit and a drive control unit that drive the radio wave transmission unit and the radio wave reception unit. The drive mechanism unit further includes a known drive source and a mechanism unit that transmits a driving force from the drive source.
The drive control unit is configured to detect a heartbeat signal or a respiratory signal in the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal generated from the reflected wave from the person. When the signal is not input, the drive mechanism is controlled by changing the direction of the antenna so that each signal has a detectable level.

The physical information measuring device of the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the spirit of the present invention.
For example, in the above-described embodiment, the rectangular bed has been described as an example of the base. However, the base is not limited thereto, and various types such as a reclining chair and a plate-like body on which each member can be installed can be adopted.
In the above-described embodiment, the radio wave irradiation unit and the radio wave reception unit have antennas separately. However, a configuration in which one antenna is shared may be used.
Moreover, it may not be connected to the alarm device, and may be connected to various devices such as other display devices as long as the situation can be notified to others.
A subject detection member for detecting a person may be arranged on the bed. This object detection member can be constituted by, for example, a sheet-like sensor that detects whether or not the person is away from the bed B based on the weight (body weight) of a person, that is, a so-called floor sensor (a heel sensor). As for the bed leaving sensor, for example, a known product (“Technos Japan Co., Ltd. | For falling / falling measures! Bed Call”, “online”, September 9, 2003, Technos Japan Co., Ltd., “January 2009 16-day search ”, URL: http://www.technosj.co.jp/alarm/bc.html).
Part or all of the control unit 25 and the amplification conversion device may be built in the radio wave analysis unit.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
Using the physical information measuring apparatus according to the present invention, the person was allowed to sleep on the base and the respiration and heart rate were measured. The results are shown in FIGS. As shown in FIG. 6, data on the abdomen, chest, and heart rate were obtained, and the phase difference between the chest signal and the abdomen signal could be clearly grasped.
The heart rate is shown in FIG. Compared with the Holter electrocardiograph (FIG. 7 (a)), which is a classic heart rate measurement, measurement was possible without significant difference. In addition, as shown in FIG. 7C, weak pulse wave vibration data could be detected even when there was a high frequency of body movement.
Further, FIG. 9 shows the result of viewing the phase difference. As shown in FIG. 9, both central apnea and obstructive apnea could be detected.

  The present invention is useful when a doctor, a nurse, or the like confirms the safety of an inpatient in a hospital room in a hospital such as an examination room or a nurse station or outside the hospital when going out or returning home. Further, for example, it is useful when a home caregiver confirms the safety of a care recipient (care recipient) in a separate room at home or in a remote place when going out. It is also useful when observing in a non-contact state, for example, for the study of the ecology of animals such as bears hibernating in a zoo.

1 Physical Information Measuring Device, 10 Base, 20, 30 Microwave Transceiver, 40 Radio Wave Analysis Unit

Claims (6)

An elongated substrate;
A plurality of radio wave irradiation units arranged at different positions of the base body and radiating radio waves of the same frequency band toward the detection target;
A radio wave receiving unit that receives a radio wave containing physical information including a detection target biological signal having periodicity, the radio wave emitted from the radio wave irradiation unit being reflected by the detection target;
A radio wave analysis unit for analyzing the radio wave received by the radio wave reception unit,
A physical information measuring device for acquiring physical information related to detection target breathing and heartbeat,
The radio wave irradiation unit is located in the central region in the longitudinal direction of the substrate, and an abdominal radio wave irradiation unit that radiates radio waves to the abdomen to be detected;
The abdominal radio wave irradiation unit includes a chest radio wave irradiation unit that is installed apart from the abdomen in the longitudinal direction of the base and radiates radio waves to a chest to be detected.
The radio wave analysis unit
The abdominal reflected radio wave and the chest reflected radio wave are used to determine an output signal during normal breathing under a predetermined condition, and the determined output signal amplitude during normal breathing is recorded as a baseline, and an amplitude reduction rate from the baseline. The physical information measuring device according to claim 1, wherein an apnea event or a hypopnea event in which an apnea state and a hypopnea state are suspected is determined based on the above.
The radio wave analysis unit
The phase of the abdominal reflected radio wave formed by the radio wave emitted from the abdominal radio wave irradiation unit being reflected by the abdomen of the detection target;
The body information measurement according to claim 1 or 2, wherein obstructive apnea is determined from a phase of a chest reflected radio wave formed by reflecting a radio wave emitted from the chest radio wave irradiating unit on the chest to be detected. apparatus.
The radio wave analysis unit
Whether or not the heart rate increases after a predetermined time has elapsed after the end of a hypopnea event or apnea event determined to be an apnea or hypopnea based on the amplitude decrease rate from the baseline. 3. The physical information measuring apparatus according to claim 2, wherein the heart rate data is recognized, and when there is an increase in the heart rate over a predetermined range, it is determined that the patient is in an apnea state or a hypopnea state.
further,
A control unit for controlling the radio wave transmission unit and the radio wave reception unit;
The control unit
A first input signal is detected from an abdominal reflected radio wave formed by the radio wave emitted from the abdominal radio wave irradiation unit being reflected by the abdomen of the detection target,
A second input signal is detected from the chest reflected radio wave formed by the radio wave emitted from the chest radio wave irradiating part being reflected by the chest to be detected;
Generating a first I channel signal and a first Q channel signal orthogonal to each other from the first input signal;
Generating a second I channel signal and a second Q channel signal orthogonal to each other from the second input signal;
The radio wave analysis unit
Calculating the spectral densities of the first I channel signal, the first Q channel signal, the second I channel signal and the second Q channel signal, respectively;
From the first I channel signal, the first Q channel signal, the second I channel signal, and the second Q channel signal, the prominent peaks of each spectral density at the same time within the main band of the detection target biological signal. Select the signal with the least number of
The physical information measuring device according to any one of claims 1 to 4, wherein the physical information measuring device functions to extract physical information about respiration and heartbeat from the selected signal.
6. The radio wave analysis unit detects a change in condition based on a change amount from a normal value set by measuring a respiratory rate and a heart rate in advance for each individual. The physical information measuring device described.