WO2023112294A1 - Vital sign measurement device, vital sign measurement method, and vital sign measurement system - Google Patents

Abstract

The present invention provides a vital sign measurement device (20) comprising: a signal acquisition unit (21) for acquiring, from antennas (11-1) to (11-N) that receive waves reflected by objects, a reception signal of the reflected waves; and a Fourier transform unit (22) for performing a Fourier transform in the time direction on the reception signal acquired by the signal acquisition unit (21). The vital sign measurement device (20) also comprises: a map calculation unit (23) for using a signal that has been Fourier-transformed by the Fourier transform unit (22) to calculate a two-dimensional azimuth map of complex electrical power corresponding to each of a plurality of distance bins from the vital sign measurement device (20); and a vital sign estimation unit (24) for identifying, on the basis of the time change in the two-dimensional azimuth map of the complex electrical power corresponding to each of the distance bins calculated by the map calculation unit (23), the position where a subject included among the object is present, and estimating vital signs of the subject from the time change in the phase of the complex electrical power for the position where the subject is present.

Description

Vital measuring device, vital measuring method and vital measuring system

The present disclosure relates to a vital measurement device, a vital measurement method, and a vital measurement system.

There is a measuring device that measures the vitals of a subject (see Patent Document 1). The measuring device transmits microwaves to a person to be measured who is present in the room, receives the reflected waves, which are the microwaves after being reflected by the person to be measured, and outputs the received signals of the reflected waves. It has Further, the measuring device includes a first mixer for extracting an in-phase signal included in the received signal output from the antenna, and a first mixer for extracting a quadrature signal included in the received signal output from the antenna. 2 mixers and a signal processor for generating a complex signal including the in-phase signal and the quadrature signal.
When the microwave transmitted from the antenna is reflected not only by the person being measured but also by the wall in the room, the complex signal generated by the signal processing device is similar to the complex signal related to the wave reflected by the person being measured. , and a complex signal related to the wave reflected by the wall are superimposed. Since the wall is a stationary object, the phase of the complex signal related to the wave reflected by the wall is constant. On the other hand, since the subject's chest reciprocates with respiration, the phase of the complex signal related to the wave reflected by the subject changes over time. The signal processing device acquires a complex signal related to the wave reflected by the subject by removing the complex signal having a constant phase from the generated complex signals, and obtains the complex signal related to the wave reflected by the subject. to detect the vitals of the subject.

Japanese Patent Application Laid-Open No. 2020-157000

In the measuring device disclosed in Patent Document 1, if a plurality of subjects are present in the room, the complex signals related to the vitals of the subjects are superimposed on each other. Even if the signal processing apparatus removes the complex signal with a constant phase from the generated complex signals, it cannot separate the complex signals related to the waves reflected by the subjects. Therefore, there is a problem that the signal processing device cannot detect the vitals of each subject.

DISCLOSURE OF THE INVENTION The present disclosure has been made in order to solve the above-described problems. Aim to get a method.

A vital measurement apparatus according to the present disclosure includes a signal acquisition unit that acquires a received signal of a reflected wave from an antenna that receives a reflected wave from a target object; and a conversion unit. In addition, the vital measurement device includes a map calculation unit that calculates a two-dimensional azimuth map of complex power corresponding to each of the plurality of distance bins from the vital measurement device using the signal after the Fourier transform by the Fourier transform unit; Based on the time change of the two-dimensional azimuth map of the complex power corresponding to each distance bin calculated by the calculation unit, the position where the person to be measured is included in the target object is identified, and the position where the person to be measured exists is determined. a vital estimator for estimating the vitals of the person to be measured from the time change of the phase of the complex power at the position where the measurement is performed.

According to the present disclosure, even if there are multiple subjects, the vitals of each subject can be detected.

1 is a configuration diagram showing a vital measurement system including a vital measurement device 20 according to Embodiment 1. FIG. 2 is a hardware configuration diagram showing hardware of the vital measurement device 20 according to Embodiment 1. FIG. 2 is a hardware configuration diagram of a computer when the vital measurement device 20 is implemented by software, firmware, or the like. FIG. 4 is a flowchart showing a vital measurement method, which is a processing procedure of the vital measurement device 20. FIG. FIG. 4 is an explanatory diagram showing up-chirp signals Tx(1) to Tx(N) generated by a signal generator 12a in respective transmission cycles c (c=1, . . . , C); FIG. 4 is an explanatory diagram showing N signals S(r, g, h, c) after Fourier transform in a certain transmission cycle c; FIG. 4 is an explanatory diagram showing a two-dimensional orientation map of complex power CP(r, az, el, c) corresponding to respective range bins r (r=1, . . . , R); FIG. 10 is an explanatory diagram showing temporal changes in phase in complex power CP(r, az, el, c) belonging to the same distance bin r and belonging to the same two-dimensional direction (az, el); FIG. 10 is an explanatory diagram showing a phase change signal θ(r, c) calculated by an existence position specifying unit 25; FIG. 4 is an explanatory diagram showing an example of a respiratory spectrum S _RR (r, sf); It is explanatory drawing which shows an example of a scalogram. FIG. 4 is an explanatory diagram showing an example of a two-dimensional spectrum W(r, f, sf) in the slow time direction; FIG. 7 is an explanatory diagram showing maximum ratio combining processing by a heart rate estimating unit 28; 4 is an explanatory diagram showing an example of a heartbeat spectrum S _HR (r, sf) obtained by a heart rate estimator 28; FIG. FIG. 11 is a configuration diagram showing a vital measurement system including a vital measurement device 20 according to Embodiment 2; 2 is a hardware configuration diagram showing hardware of a vital measurement device 20 according to Embodiment 2. FIG. FIG. 4 is an explanatory diagram showing up-chirp signals Tx(1) to Tx(N) with a number of hits Q generated by a signal generator 12a; FIG. 18A shows reception data S (t, g, h, c) acquired by the signal acquisition unit 21 after transmission waves are radiated from the antennas 11-1 to 11-N by a TDM (Time Division Multiplexing) method. FIG. 18B is an explanatory diagram showing reception data S′(t, g, h, c) after AD offset correction _{; FIG.} It is an explanatory view showing (t, g, h, c). FIG. 11 is a configuration diagram showing a vital measurement system including a vital measurement device 20 according to Embodiment 3; FIG. 11 is a hardware configuration diagram showing hardware of a vital measurement device 20 according to Embodiment 3;

Hereinafter, in order to describe the present disclosure in more detail, embodiments for carrying out the present disclosure will be described according to the attached drawings.

Embodiment 1.
FIG. 1 is a configuration diagram showing a vital measurement system including a vital measurement device 20 according to Embodiment 1. As shown in FIG.
FIG. 2 is a hardware configuration diagram showing hardware of the vital measurement device 20 according to the first embodiment.
The vitals measurement system shown in FIG. 1 includes a sensor 10 and a vitals measurement device 20 .
The sensor 10 includes N antennas 11-1 to 11-N, a signal transmitter 12, N circulators 13-1 to 13-N, and N signal receivers 14-1 to 14-N. . N is an integer of 2 or more.
Each of the antennas 11-1 to 11-N is a transmission/reception antenna.
In the vital measurement system shown in FIG. 1, the sensor 10 has N antennas 11-1 to 11-N in order to increase the resolution of received signals by MIMO (Multiple-Input Multiple-Output). Each of the antennas 11-1 to 11-N also serves as a transmitting antenna and a receiving antenna. However, this is only an example, and the sensor 10 may have separate transmitting and receiving antennas.

When the sensor 10 radiates a transmission wave, one antenna that radiates the transmission wave is selected from among the antennas 11-1 to 11-N.
The transmission order of transmission waves in the antennas 11-1 to 11-N is fixed. For example, the transmission order is determined in the order of antenna 11-1, antenna 11-2, . . . , antenna 11-N. However, this is only an example, and for example, the transmission order may be determined in the order of the antennas 11-N, .
Antenna 11-n (n=1, . . . , N) radiates a transmission wave associated with a transmission signal output from circulator 13-n to a space in which a target object exists. A transmitted wave emitted from the antenna 11-n is reflected by the target object. The target objects include one or more subjects k existing in the space, walls of the room forming the space, and stationary objects such as desks existing in the space. . k=1, . . . , K, where K is an integer of 1 or more.
Each of the antennas 11-1 to 11-N receives a reflected wave from the target object and outputs a received signal of the reflected wave to the circulator 13-n.

The signal transmitter 12 includes a signal generator 12a and an output destination selector 12b.
The signal transmission unit 12 sequentially selects one antenna 11-n from among the N antennas 11-1 to 11-N to radiate transmission waves.
The signal transmitter 12 outputs a transmission signal to the circulator 13-n connected to the selected antenna 11-n so that the selected antenna 11-n emits a transmission wave into space.
The signal generator 12a generates, for example, a transmission signal whose frequency changes over time or a pulse transmission signal. Transmission signals whose frequency changes over time include, for example, up-chirp signals and down-chirp signals.
The signal generator 12a outputs the transmission signal to the output destination selector 12b.
The output destination selection unit 12b generates a signal for the circulator 13-n connected to the antenna 11-n in the order of radiating the transmission wave next among the N circulators 13-1 to 13-N. outputs the transmission signal generated by the device 12a.

The circulator 13-n (n=1, . . . , N) outputs the transmission signal output from the output destination selector 12b to the antenna 11-n.
Also, the circulator 13-n outputs the received signal output from the antenna 11-n to the signal receiver 14-n.

The signal receiver 14-n (n=1, . . . , N) performs reception processing on the received signal output from the circulator 13-n. The reception processing includes, for example, processing for down-converting the frequency of the received signal and processing for converting the frequency-converted received signal from an analog signal to a digital signal.
The signal receiver 14-n outputs the received data S(t, g, h, c), which is a digital signal, to the vital measurement device 20. FIG.
t is the reception time of the reflected wave by the antenna 11-n. g is a variable for identifying the antenna 11-n that radiated the transmission wave, where g=1, . . . , N; h is a variable that identifies the antenna 11-n that received the reflected wave, where h=1, . . . , N; c is a variable that identifies the transmission cycle of the transmission wave by the antennas 11-1 to 11-N, where c=1, . C is an integer of 2 or more.

The vital measurement device 20 includes a signal acquisition section 21 , a Fourier transform section 22 , a map calculation section 23 and a vital estimation section 24 .
The signal acquisition unit 21 is implemented by, for example, the signal acquisition circuit 31 shown in FIG.
The signal acquisition unit 21 acquires the reception data S(t, g, h, c) as the reception signal of the reflected wave from each of the signal reception units 14-1 to 14-N, and obtains the reception data S(t, g , h, c) to the Fourier transform unit 22 .

The Fourier transform unit 22 is realized by, for example, a Fourier transform circuit 32 shown in FIG.
Each time the signal acquisition unit 21 acquires the reception data S(t, g, h, c) from the signal reception units 14-1 to 14-N, the Fourier transform unit 22 converts the reception data S(t , g, h, and c) in the time direction. Fourier transform includes, for example, Fast Fourier Transform (FFT) or Discrete Fourier Transform (DFT).
The Fourier transform unit 22 outputs the signal S(r, g, h, c) after each Fourier transform to the map calculator 23 . r is a variable that identifies the distance bin from the vital measurement device 20; r=1, . . . , R. R is an integer of 2 or more.

The map calculator 23 is implemented by, for example, a map calculator circuit 33 shown in FIG.
Each time the Fourier transform unit 22 Fourier transforms the received data S(t, g, h, c), the map calculator 23 converts the Fourier transform signal S(r, g, h, c ) to compute a two-dimensional orientation map of the complex power CP(r, az, el, c) corresponding to each range bin r (r=1, . . . , R) from the vital measurement device 20 .
The map calculator 23 outputs the two-dimensional orientation map of the complex power CP(r, az, el, c) corresponding to each distance bin r to the vital estimator 24 .

The vital estimation unit 24 is realized by, for example, the vital estimation circuit 34 shown in FIG.
The vitals estimation unit 24 includes an existence position identification unit 25 and a vitals estimation processing unit 26 .
The map calculator 23 of the vital estimator 24 calculates a two-dimensional azimuth map of the complex power CP (r, az, el, c) corresponding to each distance bin r (r=1, . . . , R). A two-dimensional orientation map is obtained each time.
The vital estimator 24 calculates the subject k (k= 1, . . . , K) are located.
The vital estimator 24 estimates the vitals of each subject k from the phase change over time of the complex power CP(r, az, el, c) at the position where each subject k is present. .

The existence position identifying unit 25 obtains a two-dimensional direction map of the complex power CP (r, az, el, c) corresponding to each distance bin r (r=1, . . . , R) by the map calculating unit 23. A two-dimensional orientation map is acquired each time it is calculated.
The existence position specifying unit 25 determines each subject k (k=1, , K) are located.
The presence position specifying unit 25 generates a phase change signal θ(r, c) indicating the time change of the phase of the complex power CP(r, az, el, c) at the position where each subject k is present. Output to the vital estimation processing unit 26 .

The vitals estimation processing unit 26 includes a respiratory rate estimation unit 27 and a heart rate estimation unit 28 .
Based on the phase change signal θ(r, c) for each subject k (k=1, . Estimate the vitals of subject k.
The respiratory rate estimator 27 estimates the respiratory rate RR of each subject k based on the phase change signal θ(r, c) for each subject k.
The heart rate estimator 28 estimates the heart rate HR of each subject k based on the phase change signal θ(r, c) for each subject k.

In FIG. 1, each of the signal acquisition unit 21, the Fourier transform unit 22, the map calculation unit 23, and the vital estimation unit 24, which are components of the vital measurement device 20, is realized by dedicated hardware as shown in FIG. Assuming something. That is, it is assumed that the vital measurement device 20 is implemented by a signal acquisition circuit 31, a Fourier transform circuit 32, a map calculation circuit 33, and a vital estimation circuit .
Each of the signal acquisition circuit 31, the Fourier transform circuit 32, the map calculation circuit 33, and the vital estimation circuit 34 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, or an ASIC (Application Specific Integrated Circuit). , FPGA (Field-Programmable Gate Array), or a combination thereof.

The components of the vital measurement device 20 are not limited to those realized by dedicated hardware, but the vital measurement device 20 may be realized by software, firmware, or a combination of software and firmware. good too.
Software or firmware is stored as a program in a computer's memory. A computer means hardware that executes a program, for example, a CPU (Central Processing Unit), a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a processor, or a DSP (Digital Signal Processor). do.

FIG. 3 is a hardware configuration diagram of a computer when the vital measurement device 20 is implemented by software, firmware, or the like.
When the vital measurement device 20 is realized by software or firmware, a program for causing a computer to execute each processing procedure in the signal acquisition unit 21, the Fourier transform unit 22, the map calculation unit 23, and the vital estimation unit 24 is stored in the memory. 41. Then, the processor 42 of the computer executes the program stored in the memory 41 .

2 shows an example in which each component of the vital measurement device 20 is implemented by dedicated hardware, and FIG. 3 shows an example in which the vital measurement device 20 is implemented by software, firmware, or the like. . However, this is only an example, and some of the components of the vital measurement device 20 may be implemented by dedicated hardware, and the remaining components may be implemented by software, firmware, or the like.

Next, the operation of the vital measurement system shown in FIG. 1 will be described.
FIG. 4 is a flow chart showing a vital measurement method, which is a processing procedure of the vital measurement device 20. As shown in FIG.
The signal generator 12a of the signal transmission unit 12 uses, as a transmission signal, for example, a frequency modulated continuous wave (FMCW) method or a fast chirp modulation (FCM: Fast-Chirp Modulation) method. A signal or down-chirp signal is generated.
In the vital measurement system shown in FIG. 1, the signal generator 12a, as shown in FIG. The up-chirp signal Tx(n) is repeatedly generated for the same amount of time. Therefore, the signal generator 12a generates a total of N×C up-chirp signals Tx(n).
FIG. 5 is an explanatory diagram showing up-chirp signals Tx(1) to Tx(N) generated by the signal generator 12a in each transmission cycle c (c=1, . . . , C). In the example of FIG. 5, N=3.
The signal generator 12a up-converts the frequency of the generated up-chirp signal Tx(n) (n=1, . (n) and output to the output destination selection unit 12b. The high frequency band is, for example, a millimeter wave band of about 30 to 300 GHz.

The output destination selector 12b acquires the transmission signal Tx'(n) from the signal generator 12a in each transmission cycle c (c=1, . . . , C).
The output destination selection unit 12b outputs the transmission signal to the circulator 13-n connected to the antenna 11-n in the order of radiating the transmission wave next among the N circulators 13-1 to 13-N. Output Tx'(n).
For example, if the antenna 11-n in the order to radiate the transmission wave next is the antenna 11-1, the output destination selection unit 12b outputs the transmission signal Tx′(1) to the circulator 13-1, and then transmits it. If the antenna 11-n in order to radiate waves is the antenna 11-2, it outputs the transmission signal Tx'(2) to the circulator 13-2.
Further, the output destination selection unit 12b outputs the transmission signal Tx'(N) to the circulator 13-N, for example, if the antenna 11-n in the order to radiate the transmission wave next is the antenna 11-N.

Circulator 13-n (n=1, . . . , N) receives transmission signal Tx'(n) from output destination selector 12b and outputs transmission signal Tx'(n) to antenna 11-n.
When receiving the transmission signal Tx'(n) from the circulator 13-n, the antenna 11-n (n=1, . radiate into the space in which A transmitted wave emitted from the antenna 11-n is reflected by the target object. That is, the transmitted wave radiated from the antenna 11-n is reflected by each person k to be measured, and is also reflected by walls or the like forming the space.
In each transmission cycle c (c=1, . Each of the antennas 11-1 to 11-N receives the reflected wave N times in each transmission cycle c.
The antenna 11-n (n=1, . . . , N) outputs the received signal of each reflected wave to the circulator 13-n.
The circulator 13-n (n=1, . . . , N) outputs the received signal output from the antenna 11-n to the signal receiver 14-n.

The signal receiver 14-n (n=1, . . . , N) receives N received signals output from the circulator 13-n in each transmission cycle c (c=1, . receive processing for each of
The signal receiving unit 14-n performs reception processing on the received signal, for example, down-converts the frequency of the received signal to a frequency in the intermediate frequency band, and converts the frequency-converted received signal from an analog signal to a digital signal. process.
The signal receiver 14-n outputs the reception data S(t, g, h, c), which are N digital signals, to the vital measurement device 20 in each transmission cycle c.
As a result, in each transmission cycle c (c=1, . . . , C), a total of N×N (=G×H) received data S ( t, g, h, c) are provided to the vital measurement device 20 .

The signal acquisition unit 21 of the vital measurement device 20 receives N×N pieces of received data S ( t, g, h, c) are obtained (step ST1 in FIG. 4).
The signal acquisition unit 21 outputs N×N received data S(t, g, h, c) to the Fourier transform unit 22 in each transmission cycle c.

The Fourier transform unit 22 acquires N×N reception data S(t, g, h, c) from the signal acquisition unit 21 in each transmission cycle c (c=1, . . . , C). .
The Fourier transform unit 22 selects each antenna 11-n (n=1, . . , N) are retrieved.
In each transmission cycle c, the Fourier transform unit 22 Fourier transforms each of the N received data S (t, g, h=n, c) associated with each antenna 11-n in the time direction (FIG. 4 step ST2).
In each transmission cycle c, each of the N received data S(t, g, h=n, c) associated with each antenna 11-n is Fourier transformed by the Fourier transform unit 22 to obtain N A signal S(r, g, h, c) after the Fourier transform of is generated.
The signal S(r, g, h, c) after the Fourier transform by the Fourier transform unit 22 is a signal representing the complex power corresponding to the distance bin r, as shown in FIG.
FIG. 6 is an explanatory diagram showing N signals S(r, g, h, c) after Fourier transform in a certain transmission cycle c.
In FIG. 6, the horizontal axis indicates distance bins, and the vertical axis indicates complex power.
The Fourier transform unit 22 outputs N signals S(r, g, h, c) after the Fourier transform to the map calculator 23 in each transmission cycle c.

The map calculator 23 acquires N Fourier-transformed signals S (r, g, h, c) from the Fourier transform unit 22 in each transmission cycle c (c=1, . . . , C). do.
In each transmission cycle c, as shown in FIG. 7, the map calculator 23 calculates distance bins r (r=1, .multidot. . . , R), a two-dimensional azimuth map of the complex power CP(r, az, el, c) is calculated (step ST3 in FIG. 4).
FIG. 7 is an explanatory diagram showing a two-dimensional orientation map of the complex power CP(r, az, el, c) corresponding to each range bin r (r=1, . . . , R).
In FIG. 7, the horizontal axis indicates the azimuth direction, and the vertical axis indicates the elevation direction.
Specifically, the map calculation unit 23 performs two-dimensional angle measurement processing by DBF (Digital Beam Forming) for each distance bin r on the signals S (r, g, h, c) after the Fourier transform. . A two-dimensional azimuth map indicating the complex power CP(r, az, el, c) for the two-dimensional azimuth (az, el) is obtained by the map calculation unit 23 performing two-dimensional angle measurement processing. The two-dimensional angle measurement processing here is two-dimensional angle measurement processing in the azimuth direction and the elevation direction. Further, the map calculator 23 uses DBF as an angle measurement method. However, this is only an example, and the map calculation unit 23 may perform two-dimensional angle measurement processing using another angle measurement method such as the Capon method. Note that the two-dimensional angle measurement process itself is a well-known technique, and detailed description thereof will be omitted.
In each transmission cycle c, the map calculator 23 acquires N Fourier-transformed signals S(r, g, h, c). If so, N×1000 two-dimensional orientation maps are calculated from N signals S(r, g, h, c) after Fourier transform.
The map calculator 23 performs synthesis processing of N two-dimensional orientation maps corresponding to each distance bin r. Synthesis processing of N two-dimensional orientation maps corresponding to each distance bin r includes, for example, complex power CP(r, az, el, c) or averaging of complex powers CP(r, az, el, c) of the same two-dimensional direction.
The map calculator 23 outputs the synthesized two-dimensional azimuth map corresponding to each distance bin r to the vital estimator 24 in each transmission cycle c.

The existence position identifying unit 25 of the vitals estimating unit 24 receives from the map calculating unit 23, in each transmission cycle c (c=1, . Get an orientation map.
The existence position specifying unit 25 determines the measured person k (k=1, . is located (step ST4 in FIG. 4).
The position identification processing by the existence position identification unit 25 will be specifically described below.

Although the reflected wave from the subject k (k=1, . , the majority of the complex power CP(r,az,el,c) is the power of the respiratory signal. A respiratory signal is a signal that indicates phase fluctuation caused by the reciprocating motion of the chest of the subject k. Therefore, the complex powers CP(r, az, el, c) belonging to the same range bin r and belonging to the same two-dimensional orientation (az, el) are shown in FIG. Circumferentially reciprocating motion over time.
FIG. 8 is an explanatory diagram showing temporal changes in phase in complex power CP(r, az, el, c) belonging to the same range bin r and belonging to the same two-dimensional direction (az, el). be. In FIG. 8, the complex power CP(r, az, el, c) performs circular reciprocating motion in the complex signal space.
In FIG. 8, ● indicates the phase θ(r, az, el, c) of the complex power CP(r, az, el, c) in the transmission cycle c=1 to C, and C ● are plotted. there is

The position identification unit 25 determines the phase of the complex power CP (r, az, el, c) for the two-dimensional orientation (az, el) corresponding to each distance bin r (r=1, . . . , R). A fitting circle Circ(r, az, el) drawn by the temporal change of is calculated.
Specifically, the presence position identifying unit 25 assumes that the complex data indicating the complex power CP(r, az, el, c) of the transmission cycle c (c=1, . . . , C) is s _c , The optimal fitting circle Circ(r, az, el) is calculated by finding α and β that minimize the evaluation function J(α, β) shown in the following equation (1). α is the center of the fitting circle Circ(r,az,el) and β is the radius of the fitting circle Circ(r,az,el). The subscript c of s _c is a variable indicating the transmission cycle.
The number of fitting circles Circ(r, az, el) calculated by the existence position specifying unit 25 is R×AZ×EL. AZ is the number of cells corresponding to the resolution in the azimuth direction of the complex data _sc , and EL is the number of cells corresponding to the resolution in the elevation direction of the complex data _sc .

The evaluation function J (α, β) can be expressed in a matrix format as shown in the following equation (2) by transforming the equation.

In equation (2), * is a mathematical symbol representing complex conjugate.

The location identifying unit 25 estimates the parameter vector p shown in Equation (2) using the method of least squares, as shown in Equation (3) below.

In equation (3), + is a mathematical symbol representing a pseudo-inverse matrix. "~" displayed above the letter p is a symbol indicating the result of estimating the parameter vector p.

Assuming that the estimation result of the parameter vector p is represented by the following equation (4), the existence position specifying unit 25 calculates the fitting circle Circ We can find the center α of (r, az, el) and the radius β of the fitting circle Circ(r, az, el). Once the center α of the fitting circle Circ(r, az, el) and the radius β of the fitting circle Circ(r, az, el) are obtained, the fitting circle Circ(r, az, el) is calculated. Become.

In equations (5) and (6), Re(□) represents the real part of □ which is a complex number, and Im(□) represents the imaginary part of □ which is a complex number. .
Here, the existence position specifying unit 25 calculates a fitting circle Circ(r, az, el) using a circle fitting method called Kasa fit. However, this is only an example, and the existence position specifying unit 25 uses a circle fitting method such as Pratt fit, Taubin fit, or Hyper fit to calculate the fitting circle Circ(r, az, el). may

Next, the existence position specifying unit 25 calculates a fitting error E(az, el), which is the error of the fitting circle Circ(r, az, el), as shown in the following equation (7).

In equation (7), S(r, az, el, c) is the two-dimensional azimuth spectrum, which is divided into range bins r corresponds to the complex power CP(r,az,el) for the two-dimensional orientation (az,el) corresponding to .
α(r,az,el) is the center of the fitting circle Circ(r,az,el) and β(r,az,el) is the radius of the fitting circle Circ(r,az,el).

If the respiration signal indicating the respiration of the subject k and the heartbeat signal indicating the heartbeat of the subject k are superimposed on the reflected wave, the radius β of the fitting circle Circ(r, az, el) increases, Also, the fitting error E(az, el) is reduced. On the other hand, if the reflected wave is a reflected wave from a stationary object such as a wall, the radius β of the fitting circle Circ(r, az, el) becomes small and the fitting error E(az, el) becomes large.
The existing position identifying unit 25 compares the radius β of the calculated R×AZ×EL fitting circles Circ(r, az, el) with the first threshold value _Th1 . The first threshold Th ₁ may be stored in the internal memory of the location identifying unit 25 or may be given from the outside of the vitals measuring device 20 .
The existence position identifying unit 25 determines _the fitting circle Circ(r, az, el).

Next, the existence position identifying unit 25 determines the fitting error E(az, el) of one or more fitting circles Circ(r, az, el) whose radius β is equal to or greater than the first threshold Th ₁ , and the second Compare with threshold _Th2 . The second threshold Th ₂ may be stored in the internal memory of the location identifying unit 25 or may be given from the outside of the vitals measuring device 20 .
The existence position specifying unit 25 determines that the fitting error E(az, el) is set to the second threshold value in _one or more fitting circles Circ(r, az, el) whose radius β is equal to or greater than the first threshold value Th1. A fitting circle Circ(r, az, el) that is less than or equal to Th ₂ is searched.

The existence position specifying unit 25 determines the position where each subject k (k= ₁ , . az, el) is less than or equal to the second threshold value _Th2 .
The presence position specifying unit 25 determines, as shown in FIG. , a phase change signal θ(r, c) indicating the time change of the phase in the complex power CP(r, az, el, c).
The presence position specifying unit 25 uses AD (Arctangent Demodulation) method or CSD (Complex Signal Demodulation) method can be used.

FIG. 9 is an explanatory diagram showing the phase change signal θ(r, c) calculated by the existence position identifying section 25. As shown in FIG.
In FIG. 9, the horizontal axis indicates the time corresponding to the transmission cycle c, and the vertical axis indicates the phase [rad] of the complex power CP(r, az, el, c) at the distance bin r.
The position specifying unit 25 outputs the phase change signal θ(r, c) for each subject k to the respiratory rate estimating unit 27 and the heart rate estimating unit 28, respectively.

The respiratory rate estimator 27 acquires the phase change signal θ(r, c) for each subject k (k=1, . . . , K) from the position identifying unit 25 .
The respiratory rate estimator 27 estimates the respiratory rate RR of each subject k by Fourier transforming the phase change signal θ(r, c) for each subject k (step ST5 in FIG. 4). ).
The process of estimating the respiratory rate RR by the respiratory rate estimator 27 will be specifically described below.

The waveform of the respiration signal indicating respiration of the person to be measured k is generally a sine wave. Therefore, sinusoidal fluctuations in the phase change signal θ(r, c) are due to the respiration of the subject k.
The respiratory rate estimating unit 27 performs a Fourier transform on the phase change signal θ(r, c) for each person k to be measured in the slow time direction to obtain a respiratory spectrum S _RR (r, sf) as shown in FIG. get The slow time is the transmission time of the transmission wave. The respiratory spectrum S _RR (r, sf) is the Fourier transform result of the phase change signal θ(r, c), where sf is the frequency in the slow time direction.
FIG. 10 is an explanatory diagram showing an example of the respiratory spectrum S _RR (r, sf).
In FIG. 10, the horizontal axis is the respiratory rate RR [bpm], and the vertical axis is the respiratory spectrum [dB].

The respiratory rate estimator 27 searches for a respiratory spectrum S _RR equal to or greater than the third threshold Th ₃ among the respiratory spectrum S _RR (r, sf) for each subject k. The third threshold _Th3 may be stored in the internal memory of the respiration rate estimator 27 or may be given from the outside of the vital measurement device 20 . Among the respiratory spectra S _RR (r, sf), there are one or more respiratory spectra S _RR that are equal to or greater than the third threshold Th ₃ .
The respiratory rate estimator 27 searches for a respiratory rate RR equal to or greater than the fourth threshold _Th4 among the respiratory rates RR corresponding to the respiratory spectrum _SRR equal to _{or greater} than the third threshold Th3. The fourth threshold Th ₄ may be stored in the internal memory of the respiration rate estimator 27 or may be given from the outside of the vital measurement device 20 .
The respiratory rate estimating unit 27 determines that the respiratory rate RR corresponding to the respiratory spectrum S _RR equal to or greater than the third threshold Th ₃ , the respiratory rate RR equal to or greater than the fourth threshold Th ₄ is the respiratory rate RR of the subject k. We assume that

Here, the respiratory rate estimating unit 27 determines that, among the respiratory spectrum S _RR (r, sf), the respiratory spectrum S _RR equal to or greater than the third threshold Th ₃ and the respiratory rate corresponding to the respiratory spectrum S _RR If the RR is greater than or equal to the fourth threshold _Th4 , the respiratory rate RR is assumed to be the respiratory rate RR of the subject k. However, this is only an example, and the respiratory rate estimator 27 determines that the respiratory rate RR corresponding to the maximum respiratory spectrum S _RR among the respiratory spectrum S _RR equal to or greater than the third threshold Th ₃ is determined by the subject k may be estimated to be the respiratory rate RR of .

The heart rate estimator 28 acquires the phase change signal θ(r, c) for each subject k (k=1, . . . , K) from the location identifying unit 25 .
The heart rate estimator 28 estimates the heart rate HR of the subject k based on the phase change signal θ(r, c) for each subject k (step ST6 in FIG. 4).
The estimation processing of the heart rate HR by the heart rate estimator 28 will be specifically described below.

First, the heart rate estimating unit 28 passes the phase change signal θ(r, c) for each person k to be measured through a high-pass filter (HPF) (not shown) to obtain a phase change signal θ( Remove the respiratory signal superimposed on r, c).
Next, the heart rate estimator 28 obtains a scalogram as shown in FIG. 11 by performing continuous wavelet transform on the phase change signal θ′(r, c) after removal of each respiratory signal. The scalogram is the continuous wavelet transform result of the phase-changed signal θ'(r,c) after removing the respiratory signal.
FIG. 11 is an explanatory diagram showing an example of a scalogram.
In FIG. 11, the horizontal axis is the transmission cycle c, and the vertical axis is the frequency [Hz].
In the scalogram, as shown in FIG. 11, stripes appear at positions where heartbeat signals are generated.

The heart rate estimator 28 obtains a two-dimensional spectrum W(r, f, sf) in the slow time direction as shown in FIG. 12 by Fourier transforming the absolute value of the scalogram in the slow time direction. f is the frequency component.
FIG. 12 is an explanatory diagram showing an example of the two-dimensional spectrum W(r, f, sf) in the slow time direction.
In FIG. 12, the horizontal axis is the heart rate HR [bpm], and the vertical axis is the frequency [Hz].
In the two-dimensional spectrum W(r, f, sf), as shown in FIG. 12, heartbeat signals are dispersed in a plurality of frequency components f. A heartbeat spectrum S _HR (r, sf) in which the heartbeat signal is emphasized is obtained by maximally synthesizing the spectrum of the high frequency region in which the heartbeat signal is dispersed.

The heart rate estimator 28 defines a matrix U representing high frequency components contained in the two-dimensional spectrum W(r, f, sf) for each subject k, as shown in the following equation (8). do.

(9)
In Equation (8), _fL is the lower limit frequency of the high frequency component, and _fH is the upper limit frequency of the high frequency component.

Next, as shown in FIG. 13, the heart rate estimation unit 28 generates a correlation matrix R _xx =UU ^H of the matrix U, and performs eigenvalue decomposition of the correlation matrix R _xx to obtain the first eigenvector u ₁ . H is the mathematical symbol for the Hermitian transpose.
The heart rate estimation unit 28 performs maximum ratio synthesis by projecting the matrix U in the direction indicated by the first eigenvector _u1 as shown in the following equation (10), and the heart rate spectrum as shown in FIG. Obtain S _HR (r, sf).

FIG. 13 is an explanatory diagram showing the maximum ratio combination processing by the heart rate estimator 28. As shown in FIG.
In FIG. 13, the horizontal axis is heart rate HR [bpm], and the vertical axis is frequency [Hz].
FIG. 14 is an explanatory diagram showing an example of the heartbeat spectrum S _HR (r, sf) obtained by the heart rate estimator 28. As shown in FIG.
In FIG. 14, the horizontal axis is the heart rate HR [bpm], and the vertical axis is the heart rate spectrum [dB].

The heart rate estimator 28 searches for a heart rate spectrum S _HR that is equal to or greater than the fifth threshold Th ₅ among the heart rate spectrum S HR ( _r , sf) for each subject k. The fifth threshold Th ₅ may be stored in the internal memory of the heart rate estimator 28 or may be given from the outside of the vital measurement device 20 . If subject k is present, the heartbeat spectrum _SHR is greater than or equal to the fifth threshold _Th5 .
The heart rate estimator 28 estimates that the heart rate HR corresponding to the heart rate spectrum S _HR equal to or greater than the fifth threshold Th ₅ is the heart rate HR of the subject k.

In the first embodiment described above, the signal acquiring unit 21 acquires the received signal of the reflected wave from the antennas 11-1 to 11-N that receive the reflected wave from the target object, and the received signal acquired by the signal acquiring unit 21 The vital measurement device 20 is configured to include a Fourier transform unit 22 that Fourier-transforms in the time direction. In addition, the vital measurement device 20 uses the signal after the Fourier transform by the Fourier transformation unit 22 to calculate a two-dimensional azimuth map of the complex power corresponding to each of the plurality of distance bins from the vital measurement device 20. 23, and the position where the subject included in the target object exists based on the time change of the two-dimensional azimuth map of the complex power corresponding to each distance bin calculated by the map calculation unit 23, and A vital estimating unit 24 for estimating the vitals of the person to be measured from the time change of the phase of the complex power at the position where the person to be measured is present. Therefore, even if there are a plurality of subjects, the vitals measuring device 20 can detect the vitals of each subject.

In the vital measurement device 20 shown in FIG. 1, the presence position specifying unit 25 determines that the position where each subject k is present has the radius β equal to or _greater than the first threshold value Th and the fitting error E (az , el) of the fitting circle Circ(r, az, el) that is less than or equal to the second threshold _Th2 , the azimuth direction az, and the elevation direction el. However, this is only an example, and the presence position specifying unit 25 determines the position of each person k to be measured by using a fitting circle Circ( _r , az, el), the azimuth direction az and the elevation direction el may be specified.
Further, the presence position specifying unit 25 determines the position where each subject k is present, and the fitting circle Circ( _r , az, el ), the azimuth direction az, and the elevation direction el may be specified.

Embodiment 2.
In Embodiment 2, a vital measurement apparatus 20 including a signal suppression unit 29 that suppresses a signal related to a reflected wave from a moving body, which is included in the received signal acquired by the signal acquisition unit 21, will be described.

FIG. 15 is a configuration diagram showing a vital measurement system including the vital measurement device 20 according to Embodiment 2. As shown in FIG. In FIG. 15, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, so description thereof will be omitted.
FIG. 16 is a hardware configuration diagram showing hardware of the vital measurement device 20 according to the second embodiment. In FIG. 16, the same reference numerals as those in FIG. 2 denote the same or corresponding parts, so description thereof will be omitted.

A vitals measuring device 20 shown in FIG.
The signal suppression unit 29 is implemented by, for example, a signal suppression circuit 35 shown in FIG.
Each time the signal acquisition unit 21 acquires the reception data S(t, g, h, c) from the signal reception units 14-1 to 14-N, the signal suppression unit 29 suppresses the reception data S(t , g, h, and c) are suppressed.
The signal suppression unit 29 outputs the received data S′(t, g, h, c) after each signal suppression to the Fourier transform unit 22 .

In FIG. 15, each of the signal acquisition unit 21, the signal suppression unit 29, the Fourier transform unit 22, the map calculation unit 23, and the vitals estimation unit 24, which are components of the vital measurement device 20, is provided with dedicated hardware as shown in FIG. It is assumed that it will be realized by hardware. That is, it is assumed that the vital measurement device 20 is realized by the signal acquisition circuit 31, the signal suppression circuit 35, the Fourier transform circuit 32, the map calculation circuit 33, and the vital estimation circuit .
Each of the signal acquisition circuit 31, the signal suppression circuit 35, the Fourier transform circuit 32, the map calculation circuit 33, and the vital estimation circuit 34 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, An FPGA or a combination thereof is applicable.

The components of the vital measurement device 20 are not limited to those realized by dedicated hardware, but the vital measurement device 20 may be realized by software, firmware, or a combination of software and firmware. good too.
When the vital measurement device 20 is realized by software, firmware, or the like, the computer executes the respective processing procedures in the signal acquisition unit 21, the signal suppression unit 29, the Fourier transform unit 22, the map calculation unit 23, and the vital estimation unit 24. A program for this is stored in the memory 41 shown in FIG. Then, the processor 42 shown in FIG. 3 executes the program stored in the memory 41 .

16 shows an example in which each component of the vital measurement device 20 is implemented by dedicated hardware, and FIG. 3 shows an example in which the vital measurement device 20 is implemented by software, firmware, or the like. . However, this is only an example, and some of the components of the vital measurement device 20 may be implemented by dedicated hardware, and the remaining components may be implemented by software, firmware, or the like.

Next, operation of the vital measurement system shown in FIG. 15 will be described.
In the vital measurement system shown in FIG. 1, the signal generator 12a generates up-chirp signals Tx(1) to Tx in each transmission cycle c (c=1, . (N) is generated.
In the vital measurement system shown in FIG. 15, the signal generator 12a generates signals Tx(1) to Tx(N) in each transmission cycle c (c=1, . . . , C) as shown in FIG. is repeatedly generated Q times. That is, the signal generator 12a generates signals Tx(1) to Tx(N) for hits q (q=1, . . . , Q) in each transmission cycle c. Q is an integer of 2 or more. That is, the signal generator 12a generates signals Tx(1) to Tx(N) with the number of hits Q in each transmission cycle c.
FIG. 17 is an explanatory diagram showing the up-chirp signals Tx(1) to Tx(N) with the number of hits Q generated by the signal generator 12a. In the example of FIG. 17, N=3. The number of hits Q is 16, for example.
Therefore, the antennas 11-n (n=1, . Each of the transmitted waves is radiated into the space in which the object of interest resides.

Each of the antennas 11-1 to 11-N receives N×Q reflected waves in each transmission cycle c (c=1, . . . , C).
If there is a moving object other than the person to be measured k (k=1, . Waves are also incident on the antennas 11-1 to 11-N.
The person to be measured k is, for example, a generally stationary person lying on a bed or a generally stationary person sitting on a chair or the like. A moving object is a person or the like moving in a space in which the transmitted wave is emitted.
Antennas 11-n (n=1, . . . , N) receive waves reflected by the target object in each transmission cycle c. That is, the antennas 11-n (n=1, . . . , N) receive reflected waves from the subject k and the moving object in each transmission cycle c.
Antenna 11-n (n=1, . Output to circulator 13-n.
The circulator 13-n outputs N×Q received signals output from the antenna 11-n to the signal receiver 14-n in each transmission cycle c.

The signal receiver 14-n (n=1, . Reception processing is performed on each of the received signals.
The signal receiver 14-n outputs each of the N×Q received data S(t, g, h, c) to the vital measurement device 20 in each transmission cycle c.
As a result, in the transmission cycle c=1 to C, a total of N×Q×C received data S (t, g, h, c) are received from the signal receivers 14-1 to 14-N, and the vital measuring device 20 given to

The signal acquisition unit 21 of the vital measurement device 20 receives N×Q pieces of received data S ( t, g, h, c).
The signal acquisition unit 21 outputs each of the N×Q reception data S(t, g, h, c) to the signal suppression unit 29 in each transmission cycle c.

The signal suppression unit 29 acquires N×Q reception data S(t, g, h, c) from the signal acquisition unit 21 in each transmission cycle c (c=1, . . . , C). .
The signal suppression unit 29 suppresses signals related to waves reflected by moving objects, which are included in each of the N×Q pieces of received data S(t, g, h, c) in each transmission cycle c.
The signal suppression unit 29 outputs N×Q reception data _SY (t, g, h, c) to the Fourier transform unit 22 as a signal after signal suppression in each transmission cycle c.
The signal suppression processing by the signal suppression unit 29 will be specifically described below.

FIG. 18A shows reception data S (t, g, h, c) acquired by the signal acquisition unit 21 after transmission waves are radiated from the antennas 11-1 to 11-N by a TDM (Time Division Multiplexing) method. showing.
In FIG. 18A, the horizontal axis indicates time and the vertical axis indicates amplitude. The number of virtual channels by MIMO (Multiple-Input Multiple-Output) is G×H.
As shown in FIG. 18A, the received data S(t, g, h, c) is superimposed with a DC (Direct Current) offset component caused by the receiving system hardware.
The number of reception data S(t, g, h, c) given from the signal acquisition unit 21 to the signal suppression unit 29 is N×Q in each transmission cycle c (c=1, . . . , C). is.

As shown in FIG. 18B, the signal suppression unit 29 performs an AD (Analog-to-Digital) offset for removing a DC offset component superimposed on the received data S (t, g, h, c) for each virtual channel. Make corrections. Since the AD offset correction itself is a known technique, detailed description thereof will be omitted.
FIG. 18B shows received data S′(t, g, h, c) after AD offset correction.
In FIG. 18B, the horizontal axis indicates time and the vertical axis indicates amplitude.

As shown in FIG. 18C, the signal suppression unit 29 averages G×H received data S′(t, g, h, c) after AD offset correction for each virtual channel in each transmission cycle c. become
By averaging the received data S′(t, g, h, c) by the signal suppression unit 29, the reflection by the moving body included in the received data S′(t, g, h, c) is reduced. Wave-related signals are suppressed.
In each transmission cycle c, the signal suppression unit 29 generates N received data S Y (t, g, h, c) after signal suppression as N received data _S (t, g, h, c). is output to the Fourier transform unit 22 .
FIG. 18C shows received data S _Y (t, g, h, c) after signal suppression related to reflected waves from moving objects.
In FIG. 18C, the horizontal axis indicates time and the vertical axis indicates amplitude.
Since the processing after the Fourier transform unit 22 is the same as that of the vital measurement device 20 shown in FIG. 1, the description is omitted.

In the second embodiment described above, the signal suppression unit 29 is provided for suppressing the signal related to the reflected wave from the moving body, which is included in the received signal acquired by the signal acquisition unit 21, and the Fourier transform unit 22 suppresses the signal. The vital measuring apparatus 20 shown in FIG. 15 is configured so as to Fourier transform the received signal after signal suppression by the unit 29 in the time direction. Therefore, the vital measurement device 20 shown in FIG. 15, like the vital measurement device 20 shown in FIG. , the vitals of the subject can be detected even if a moving object exists in the space.

Embodiment 3.
In Embodiment 3, a vital measuring device 20 including a moving body detection section 30 that detects a moving body based on the received signal acquired by the signal acquisition section 21 will be described.

FIG. 19 is a configuration diagram showing a vital measurement system including the vital measurement device 20 according to Embodiment 3. As shown in FIG. In FIG. 19, the same reference numerals as those in FIG. 15 denote the same or corresponding parts, so description thereof will be omitted.
FIG. 20 is a hardware configuration diagram showing the hardware of the vital measurement device 20 according to Embodiment 3. As shown in FIG. In FIG. 20, the same reference numerals as those in FIG. 16 denote the same or corresponding parts, so description thereof will be omitted.

A vitals measuring device 20 shown in FIG.
The moving body detection unit 30 is realized by, for example, a moving body detection circuit 36 shown in FIG.
The moving object detection unit 30 extracts signals related to waves reflected by the moving object, which are included in the reception data S(t, g, h, c) acquired by the signal acquisition unit 21 .
The moving object detection unit 30 detects the moving object based on the signal related to the wave reflected by the moving object.

In FIG. 19, each of the signal acquisition unit 21, the signal suppression unit 29, the Fourier transform unit 22, the map calculation unit 23, the vital estimation unit 24, and the moving object detection unit 30, which are components of the vital measurement device 20, is shown in FIG. It is assumed to be realized by dedicated hardware as shown. That is, it is assumed that the vital measuring device 20 is realized by a signal acquiring circuit 31, a signal suppressing circuit 35, a Fourier transforming circuit 32, a map calculating circuit 33, a vital estimating circuit 34, and a moving body detecting circuit .
Each of the signal acquisition circuit 31, the signal suppression circuit 35, the Fourier transform circuit 32, the map calculation circuit 33, the vital estimation circuit 34, and the moving object detection circuit 36 can be, for example, a single circuit, a composite circuit, a programmed processor, a parallel program, processors, ASICs, FPGAs, or combinations thereof.

The components of the vital measurement device 20 are not limited to those realized by dedicated hardware, but the vital measurement device 20 may be realized by software, firmware, or a combination of software and firmware. good too.
When the vital measurement device 20 is realized by software or firmware, the processing in the signal acquisition unit 21, the signal suppression unit 29, the Fourier transform unit 22, the map calculation unit 23, the vital estimation unit 24, and the moving body detection unit 30 A program for causing the computer to execute the procedure is stored in the memory 41 shown in FIG. Then, the processor 42 shown in FIG. 3 executes the program stored in the memory 41 .

20 shows an example in which each component of the vital measurement device 20 is implemented by dedicated hardware, and FIG. 3 shows an example in which the vital measurement device 20 is implemented by software, firmware, or the like. . However, this is only an example, and some of the components of the vital measurement device 20 may be implemented by dedicated hardware, and the remaining components may be implemented by software, firmware, or the like.

Next, the operation of the vital measurement system shown in FIG. 19 will be described. The vital measurement system is the same as that shown in FIG. Therefore, only the operation of the moving object detection unit 30 will be described here.

The moving object detection unit 30 acquires N×C reception data S(t, g, h, c) from the signal acquisition unit 21 in each transmission cycle c (c=1, . . . , C). do.
Based on the N×C pieces of received data S (t, g, h, c), the moving object detection unit 30 performs tracking processing for moving objects existing in space, thereby Estimates the existing position of a moving object that changes with time. Since the moving object tracking process itself is a well-known technique, detailed description thereof will be omitted.
For example, if the number of moving bodies existing in space is one, the existing position of one moving body is estimated. For example, if a first moving body and a second moving body exist in space as two moving bodies, the existing position of the first moving body and the existing position of the second moving body are estimated. do.
The moving object detection unit 30 detects the two-dimensional direction in which the moving object exists based on the estimation result of the existing position of the moving object. The two-dimensional orientation is the azimuth direction when the mobile body is viewed from the vital measurement device 20 and the elevation direction when the mobile body is viewed from the vital measurement device 20 .

Here, the moving object detection unit 30 estimates the existing position of the moving object by performing tracking processing of the moving object existing in space. However, this is only an example, and the moving body detection unit 30 Fourier transforms the N×C pieces of received data S(t, g, h, c) in the hit direction to obtain the Doppler frequency fd of the moving body as You may make it calculate. By calculating the Doppler frequency fd of the moving object, the speed of the moving object can be calculated.

In the third embodiment described above, the vital measuring device 20 shown in FIG. 19 is configured to include the moving body detection section 30 that detects a moving body based on the received signal acquired by the signal acquisition section 21 . Therefore, even if there are a plurality of subjects, the vital measurement apparatus 20 shown in FIG. , can detect moving objects.

It should be noted that the present disclosure allows free combination of each embodiment, modification of arbitrary constituent elements of each embodiment, or omission of arbitrary constituent elements in each embodiment.

The present disclosure is suitable for vital measurement devices, vital measurement methods, and vital measurement systems.

10 sensors, 11-1 to 11-N antennas, 12 signal transmitters, 12a signal generators, 12b output destination selectors, 13-1 to 13-N circulators, 14-1 to 14-N signal receivers, 20 vitals Measurement device, 21 signal acquisition unit, 22 Fourier transform unit, 23 map calculation unit, 24 vital estimation unit, 25 existence position identification unit, 26 vital estimation processing unit, 27 breathing rate estimation unit, 28 heart rate estimation unit, 29 signal suppression section, 30 mobile detection section, 31 signal acquisition circuit, 32 Fourier transform circuit, 33 map calculation circuit, 34 vital estimation circuit, 35 signal suppression circuit, 36 mobile detection circuit, 41 memory, 42 processor.

Claims (10)

1. a signal acquisition unit that acquires a received signal of the reflected wave from an antenna that receives the reflected wave from the target object;
   a Fourier transform unit that Fourier transforms the received signal acquired by the signal acquisition unit in the time direction;
   A map calculation unit that calculates a two-dimensional azimuth map of complex power corresponding to each of a plurality of distance bins from the vital measurement device using the signal after the Fourier transform by the Fourier transform unit;
   Based on the time change of the two-dimensional azimuth map of the complex power corresponding to each distance bin calculated by the map calculating unit, the position where the person to be measured is included in the target object is identified, and A vitals measuring device comprising: a vitals estimating unit for estimating the vitals of the person to be measured from the time change of the phase of the complex power at the position where the person is being measured.
2. One or more persons to be measured are included in the target object,
   The vital estimation unit is
   Based on the time change of the two-dimensional azimuth map of the complex power corresponding to each distance bin calculated by the map calculation unit, the position where each subject is located is identified, and each subject is an existing position specifying unit that outputs a phase change signal indicating the time change of the phase of the complex power at the existing position;
   2. The vitals measuring apparatus according to claim 1, further comprising a vitals estimation processing unit for estimating the vitals of each subject based on each phase change signal output from the existence position specifying unit. .
3. The existence position specifying unit
   Among the plurality of complex powers included in each of the plurality of two-dimensional orientation maps calculated by the map calculation unit, the complex powers having the same distance bin and the same two-dimensional orientation A plurality of pairs are extracted, a fitting circle is calculated that depicts the time change of the phases of the multiple complex powers contained in each pair, and the position of the person to be measured is represented by the calculated fitting circles. 3. The vital measuring device according to claim 2, wherein the positions of complex powers included in a set of fitting circles having a radius greater than or equal to the first threshold are specified.
4. The existence position specifying unit
   Among the plurality of complex powers included in each of the plurality of two-dimensional orientation maps calculated by the map calculation unit, the complex powers having the same distance bin and the same two-dimensional orientation A plurality of pairs are extracted, a fitting circle is calculated that depicts the time change of the phases of the multiple complex powers contained in each pair, and the position of the person to be measured is represented by the calculated fitting circles. 3. The vital measuring device according to claim 2, wherein the position of the complex power included in the set related to the fitting circle whose fitting error, which is the error of the fitting circle, is equal to or less than the second threshold is specified.
5. The existence position specifying unit
   Among the plurality of complex powers included in each of the plurality of two-dimensional orientation maps calculated by the map calculation unit, the complex powers having the same distance bin and the same two-dimensional orientation A plurality of pairs are extracted, a fitting circle is calculated that depicts the time change of the phases of the multiple complex powers contained in each pair, and the position of the person to be measured is represented by the calculated fitting circles. identifying the positions of the complex powers included in the set associated with the fitting circle having a radius greater than or equal to the first threshold and having a fitting error, which is the error of the fitting circle, less than or equal to the second threshold. The vitals measuring device according to claim 2, characterized by:
6. The vital estimation processing unit,
   a breathing rate estimating section for estimating the breathing rate of each subject based on each phase change signal output from the position identifying section;
   3. The vital measurement according to claim 2, further comprising a heart rate estimating section for estimating the heart rate of each subject based on each phase change signal output from the existence position identifying section. Device.
7. A signal suppression unit that suppresses a signal related to a reflected wave from a moving object, which is included in the received signal acquired by the signal acquisition unit;
   The Fourier transform unit is
   2. The vitals measuring apparatus according to claim 1, wherein the received signal after signal suppression by said signal suppression unit is Fourier-transformed in the time direction.
8. The vitals measuring apparatus according to claim 7, further comprising a moving body detection section that detects the moving body based on the received signal acquired by the signal acquisition section.
9. A signal acquisition unit acquires a received signal of the reflected wave from an antenna that receives the reflected wave from the target object,
   a Fourier transform unit Fourier transforming the received signal acquired by the signal acquisition unit in the time direction;
   A map calculation unit calculates a two-dimensional azimuth map of complex power corresponding to each of a plurality of distance bins from the vital measurement device using the signal after the Fourier transform by the Fourier transform unit,
   A vital estimator determines a position where the subject included in the target object exists, based on the time change of the two-dimensional azimuth map of the complex power corresponding to each distance bin calculated by the map calculator. A method of measuring vitals, comprising identifying and estimating the vitals of the person to be measured from changes in phase of complex power over time at a position where the person to be measured is present.
10. an antenna;
    a signal transmitter that emits a transmission wave from the antenna to a space where the target object exists;
    a signal acquisition unit that acquires a received signal of the reflected wave from the antenna that receives the reflected wave, which is a transmission wave after being reflected by the target object;
    a Fourier transform unit that Fourier transforms the received signal acquired by the signal acquisition unit in the time direction;
    A map calculation unit that calculates a two-dimensional azimuth map of complex power corresponding to each of a plurality of distance bins from the vital measurement device using the signal after the Fourier transform by the Fourier transform unit;
    Based on the time change of the two-dimensional azimuth map of the complex power corresponding to each distance bin calculated by the map calculating unit, the position where the person to be measured is included in the target object is identified, and A vitals measuring system comprising: a vitals estimating unit for estimating the vitals of the person to be measured from the time change of the phase of the complex power with respect to the position where the person is being measured.

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