JP6035813B2 - Biological monitoring apparatus, apparatus control method, and apparatus control program - Google Patents

Description

  The present invention relates to an apparatus for monitoring a living body, an apparatus control method, and an apparatus control program.

  In recent years, attention has been focused on grasping the state of breathing as one index for knowing the health condition of a subject. Respiration is broadly divided into cellular respiration and pulmonary respiration. As used herein, “breathing” means lung breathing. Lung breathing is a physiological phenomenon that takes in oxygen from the outside world and releases carbon dioxide. Respiration is also closely related to autonomic nerve activity. Breathing is also related to the state of the heart. When the mind and body are in tension, breathing tends to be shallower and breathing time tends to be shorter. On the other hand, in a relaxed state, the breathing becomes deeper and the time for each breath becomes longer.

  The breath includes an inspiration time and an expiration time. The ratio of inspiratory time and expiratory time is called the E ratio. There is a research report that the E ratio is usually preferably 1 to 2. The E ratio is also related to the airway pressure. In order to increase the airway pressure, it is possible to control the E ratio from 1: 2 to 1: 3.

  It has also been reported that appropriate breathing is effective for controlling the autonomic nerve, particularly the parasympathetic nerve, to a normal state. In addition, it has been reported that it is effective to maintain an appropriate E ratio in exercise guidance for patients with ischemic heart disease of the heart.

  It has also been emphasized to grasp the detailed state of breathing during sleep.

  As a device for measuring expiration and inspiration, there is a contact type in which a sensor is attached to a subject. As the contact type device, there are a thermistor type (temperature change detection) and a follow type, and a dedicated sensor is often used.

  Conventionally, a technique is known in which a change in scattering characteristics from the body with respect to microwaves is acquired, a power spectrum for the change is analyzed, and a respiratory rate of the body is detected (see Patent Document 1).

  In addition, there is a technique for detecting the breathing cycle of the driver by using a zero cross counter with respect to the waveform signal of the reflected wave of the microwave irradiated to the chest of the driver (see Patent Document 2).

  Further, there is a technique for measuring an inspiration time and an expiration time using a thermistor type nasal airflow sensor (see Patent Document 3).

  In addition, there is a technique in which a plurality of respiratory waveforms acquired by an impedance monitor are temporally aligned, and the start and end of an expiration period are specified based on the inflection point of the respiratory waveform (see Patent Document 4).

JP 2006-525831 A Japanese Patent Publication No. 6-69444 JP 2008-68018 A Special table 2009-530047 gazette

  According to one aspect, an object of the present invention is to provide a biological monitoring device, a device control method, and a device control program.

  According to one aspect of the present invention, there is provided a device for monitoring a living body, and in order to obtain a received signal, a receiving unit that receives an electromagnetic wave reflected from the living body, and a waveform of the received signal according to a predetermined pattern recognition rule A feature extraction unit that extracts a plurality of features, an expiration / inspiration time estimation unit that estimates an expiration time and an inspiration time of a living body based on positions of the plurality of features on a time axis, and the estimated expiration And an output unit that outputs the intake time.

  According to the embodiment, it is possible to easily monitor biological information without contact.

1 is a block diagram of an apparatus according to an embodiment of the present invention. It is a figure which shows another example of the signal period estimation part of one Embodiment. FIG. 3 is a flowchart of a method according to an embodiment. FIG. 6 shows a flowchart of another method of an embodiment. It is a figure which shows the flowchart of the signal period estimation process of one Embodiment. It is a figure which shows the relationship between each signal in FIG. 1, inhalation time, and expiration time. It is a figure which shows the pattern recognition rule for recognizing the position of inspiration / expiration. It is a figure which shows one Embodiment. It is a figure which illustrates the hardware constitutions of one Embodiment.

  Embodiments of the present invention will be described below in detail with reference to the drawings. It should be noted that the following embodiments are for understanding the invention and are not intended to limit the scope of the present invention. In addition, the following embodiments are not mutually exclusive. Therefore, it should be noted that the elements of the embodiments are also intended to be combined unless a contradiction arises. Further, in the invention according to the method and the program described in the claims, the order of the processes may be changed as long as there is no contradiction, or a plurality of processes may be performed simultaneously. Further, in the flowchart that is simply branched, either of the steps placed in parallel may be processed first. It goes without saying that these embodiments are also included in the technical scope of the invention described in the claims. It should be noted that the same components are denoted by the same reference numerals in a plurality of drawings.

  Moreover, although various embodiment of this invention demonstrated below demonstrates using the microwave as an example for electromagnetic waves, this invention is not limited to utilization of a microwave. Further, “non-contact” used in the present invention means that a device implementing the present invention can be easily separated from the body of the subject. For example, when a device is placed in a breast pocket, or the device may be brought into direct contact with the body. Alternatively, a part or all of the device that implements the present embodiment may be used while being in contact with a part of the body, or may be used by being installed in the body.

  FIG. 1 shows a block diagram of an apparatus according to an embodiment of the present invention. This apparatus includes a microwave transmission unit 110, a transmission antenna 112, a reception unit 120, a reception antenna 122, a feature extraction unit 130, an expiration / inspiration time estimation unit 150, and an output unit 160.

  Here, an outline of the operation of the embodiment will be described. Details of each component will be described later.

  First, a microwave is generated from the microwave transmission unit 110, and the microwave is radiated from the transmission antenna 112. The emitted microwave 113 reaches each tissue of the subject 100 (living body) that is the object to be monitored and reflects. A part of the reflected microwave reaches the reception antenna 122 and is sent to the reception unit 120 as an electric signal. The reception unit converts the received microwave into a reception signal S1. The received signal S1 is sent to the feature extraction unit 130. The feature extraction unit 130 recognizes a plurality of features in the reception signal S1 and sends information including at least the start and end times of expiration and the start and end times of inspiration to the expiration / inspiration time estimation unit 150. The expiratory / inspiratory time estimating unit 150 records data related to the expiratory time and the inspiratory time, and calculates, for example, an average value of these data and outputs the data to the output unit 160. In addition, the feature extraction unit may send heart rate information including the heart rate of the subject 100 to the output unit 160.

  When a weak microwave is applied to a subject, the reflected wave includes information such as breathing, heartbeat, and body movement. For example, in the case of an adult, about 500 ml of air is inhaled in one breath. For this reason, the surface of the subject's chest moves about 1 to 2 cm. In addition, movement of bones and diaphragms in the body occurs due to respiration. Microwaves are also reflected from internal organs. As the body surface and organs move, the output of the reflected wave of the microwave changes. For this reason, the reflected microwave contains information on the movement of the body surface and internal organs. In addition, the reflected microwave includes information on the movement of the heart and information on body movement.

  In FIG. 1, the feature extraction unit 130 includes a signal period estimation unit 140 (1), a waveform shaping unit 132, and a feature recognition unit 134. The waveform shaping unit 132 outputs, for example, a shaped waveform S2 by applying first-order differentiation to the received signal S1. The shaped waveform S2 is input to the feature recognition unit 134, and a plurality of feature positions of the shaped waveform S2 are specified on the time axis based on a predetermined pattern recognition rule. Note that the feature recognition unit 134 may use the respiratory cycle information from the signal cycle estimation unit 140 (1). Since the same pattern is repeated in the breathing cycle, the feature recognition unit 134 can use the breathing cycle information to improve the accuracy of feature recognition related to breathing. Details of the pattern recognition rules in the feature recognition unit 134 will be described later with reference to FIG.

  In FIG. 1, the signal period estimation unit 140 (1) will be described below. The signal cycle estimation unit 140 (1) includes a power spectrum conversion unit 142, a peak frequency identification unit 144, a filter unit 146, a heart rate information estimation unit 148, and a respiratory cycle estimation unit 149. The power spectrum conversion unit 142 applies, for example, a fast Fourier transform (FFT) to the reception signal S1, and converts the reception signal S1 into a power spectrum S4. For the conversion of S4 to a power spectrum, MEM (maximum entropy method) or the like may be used. In the obtained power spectrum S4, the peak frequency specifying unit 144 searches for a peak of a frequency related to respiration, for example, from among a plurality of peaks of the power spectrum S4. By this search, the respiratory frequency can be estimated. The estimated respiratory frequency is sent to the filter unit 146. Alternatively, as will be described later, the estimated respiration frequency may be sent to the respiration cycle estimation unit 149 via the bypass 147. The filter unit 146 may be realized by, for example, a band pass filter (BPF) having a respiratory frequency as a center frequency. Alternatively, it may be realized by a low-pass filter whose respiratory frequency is a cutoff frequency. The filter unit 146 receives the received signal S1. Therefore, the signal (S3) in the frequency band that has passed through the filter unit 146 is a signal that contains a very large amount of respiratory frequency components. The respiratory component signal S3 is transmitted to the respiratory cycle estimation unit 149. The respiratory cycle estimation unit 149 can obtain an estimated value of the respiratory cycle by removing, for example, a direct current component from the respiratory component signal S3 and specifying the zero-cross position of the signal. Information on the estimated value of the respiratory cycle is transmitted to the feature recognition unit 134 as a signal to the terminal C. Further, as described above, when the estimated respiratory frequency is input from the peak frequency specifying unit 144 to the respiratory cycle estimating unit 149 via the bypass 147, the respiratory cycle estimating unit 149 An estimated value of the respiratory cycle may be obtained from the frequency. The heart rate information estimation unit 148 also receives information on the peak frequency of the power spectrum in the heart rate frequency region from the peak frequency specifying unit 144. The heart rate information estimation unit 148 may obtain, for example, the heart rate per minute from the peak frequency of the power spectrum in the received heart rate frequency region, and transmit it to the output unit 160.

  FIG. 2 shows a modification example of the signal period estimation unit 140 (2) of the signal period estimation unit 140 (1) in FIG. It should be noted that A, B, and C in FIG. 2 correspond to A, B, and C in FIG. The signal cycle estimation unit 140 (2) includes a PLL 1 (202) including a function of a phase lock loop (PLL), a respiratory cycle information processing unit 204, p1 2 (206), and a heartbeat information processing unit 208. The reception signal S1 received from the input terminal A is input to the PLL1 (202). The PLL1 (202) is a PLL that locks in a respiration frequency band (usually a center frequency of 0.2 Hz). A signal locked to the respiration frequency is obtained by the PLL 1 (202), and the signal is sent to the respiration cycle information processing unit 204. The respiratory cycle information processing unit 204 sends information on the estimated value of the respiratory cycle to the feature recognition unit 134 as a signal to the terminal C based on the received signal. Further, PLL2 (206) is a PLL that locks to the beat frequency (usually 0.7 Hz to 2 Hz). A signal locked to the beat frequency is obtained by the PLL 2 (206), and the signal is sent to the heartbeat information processing unit 208. The heart rate information processing unit 208 may send, for example, the heart rate per minute as a signal to the terminal B to the output unit 160 based on the received signal.

  Other than the modifications of the signal cycle estimation unit shown in FIG. 2, those skilled in the art will be able to make various modifications.

  FIG. 3 shows a flowchart of a method for controlling the apparatus according to the embodiment of the present invention.

  In step 310, the reception signal S1 is acquired from the microwave received by the receiver.

  In step 320, the characteristics of the received reception signal S1 are extracted. Features include start and end times of exhalation and start and end times of inspiration. Step 320 further includes steps 322 and 324.

  In step 322, a first derivative is applied to the received signal S1. In this embodiment, the first order differentiation is used, but a general Nth order differentiation (N is an integer) may be applied. Depending on the order of differentiation, the feature extraction method may be different.

  In step 324, features are extracted according to predetermined pattern recognition rules. Features include exhalation start and end times and inspiration start and end times.

  In step 330, respiration information including an expiration time and an inspiration time is estimated from the extracted features. The expiration time can be obtained from the start and end times of expiration. The intake time can also be obtained by the same method.

  FIG. 4 shows a flowchart of another method of the embodiment. It should be noted that the steps already described in FIG. 3 are given the same reference numerals.

  In step 400, the signal period of the received signal S1 is estimated. Here, in particular, the respiratory cycle is estimated. The estimated respiratory cycle is used in feature recognition by the pattern recognition rule in step 324. In most cases, the received signal S1 and its differentiated signal are repeated in an approximate pattern depending on the breathing cycle. Accordingly, in step 400, the feature recognition in step 324 can be performed more easily by obtaining the respiratory cycle.

  Other steps in FIG. 4 are the same as those in FIG.

  FIG. 5 shows a flowchart of a more specific processing method related to the signal period estimation process (step 400) of the embodiment. It should be noted that D and E in FIG. 5 correspond to D and E in FIG.

  In step 510, the power spectrum of the received signal S1 is acquired. As described above, FFT, MEM, or the like may be used for calculating the power spectrum.

  In step 520, a plurality of peak frequencies of the power spectrum are extracted.

  In step 530, the extracted peak frequency corresponding to the respiratory frequency is extracted. Usually, the center frequency of respiration is around 0.2 Hz. Therefore, a frequency having a power spectrum peak in the vicinity of the center frequency may be employed as the respiratory frequency.

  In step 540, the received signal S1 is filtered using a band pass filter (or a low pass filter having a cut-off frequency) having the acquired respiratory frequency as a center frequency, and a filtered signal is extracted.

  In step 550, a respiratory cycle is obtained from the extracted filtered signal. Then, the process continues to step 322 in FIG.

  In step 350, the respiratory frequency may be directly processed in step 550 via the path 532. This path 532 shows a flow corresponding to the bypass path 147 in FIG.

  In step 580, the peak frequency corresponding to the heartbeat frequency is extracted from the extracted peak frequencies. Usually, since the heartbeat frequency is 0.7 Hz to 2 Hz, a frequency having a peak of the power spectrum located in this range or in the vicinity of this range may be adopted as the heartbeat frequency. This heartbeat frequency may be converted into, for example, a heart rate per minute and output.

  FIG. 6 shows an example of the signal waveform of each signal (S1, S2, S3, and S4) in FIG. 1, and the relationship between the expiration time and the inspiration time.

  In FIG. 6, (S1) shows an example of the waveform of the received signal S1. This waveform may be, for example, a received microwave amplitude modulation signal. Moreover, you may perform a filtering process (for example, high cut filter process) for the removal of noise etc. as needed.

  The signal (S2) shows an example of the shaped waveform S2 of the waveform shaping unit 132 in FIG. In this example, a waveform obtained by performing first-order differentiation on the received signal S1 is shown. Details of the points (a1 to e3) indicated in each part of the signal in this waveform will be described later with reference to FIG. Here, Ts1, Ts2, and Ts3 indicate the estimated intake time, respectively. Tb1, Tb2, and Tb3 indicate estimated expiration times, respectively.

  The signal (S3) shows an example of the respiratory component signal S3 of the filter unit 146 in FIG. In this example, the points where the respiratory component signal S3 zero-crosses from minus to plus are indicated as W1, W2, and W3, respectively. A period T12 from W1 to W2 and a period T23 from W2 to W3 correspond to the time of one breath. It should be noted that since the respiratory component signal S3 passes through the bandpass filter, there is a phase shift between the reception signal S1 and the shaped waveform S2. As can be seen by comparing the shaped waveform S2 and the respiratory component signal S3, for example, the respiratory period T12 includes one expiration time Tb1 and one inspiration time Ts2, and the respiratory period T23 includes one expiration period. It can be seen that the time Tb2 and one intake time Ts3 are included.

  A graph (S4) shows an example of a graph of a power spectrum obtained in the power spectrum conversion unit 142 in FIG. As can be seen from the graph, the power spectrum includes a plurality of peaks. The first peak, counting from frequency 0, corresponds to the spectrum associated with respiration. The frequency f1 is about 0.25 Hz. The third peak that appears corresponds to the spectrum associated with the heartbeat. The frequency f2 is about 0.8 Hz. From this information, it can be seen that the respiratory cycle is about 4 seconds and the pulse rate is about 48 per minute.

  FIG. 7 shows an example of a pattern recognition rule for recognizing the position of the inspiration / expiration on the time axis. FIG. 7 shows a shaped waveform S2 to which the first-order differentiation of the received signal S1 is applied, and symbols a, b, c, d, e, and h are shown in the waveform.

  First, the characteristics of inspiration can be found by searching for a signal pattern that satisfies a + c> | b |. And a, b, and c have the characteristic that a high peak (a negative peak is included) appears continuously. When searching for this feature, the respiratory cycle may be used effectively. That is, the patterns a, b, and c appear only once in one respiratory cycle interval. Considering the case where the pattern of a, b, and c overlaps with the start or end of one respiratory cycle and cannot be recognized, a, b, and c are shifted by shifting the position of the start or end of one respiratory cycle. It may be confirmed whether the pattern is found. In this way, a plurality of patterns a, b, and c can be found.

  Next, a pattern recognition rule for finding an expiration pattern will be described. Exhalation exists between two adjacent inspirations. Therefore, a high peak e on the plus side is searched between two intakes. There is a negative valley of h just before e. Further, the position d of the zero cross before time h is searched.

  Furthermore, the characteristics of exhalation are d> h, d + e + | h | <a + c + | b |.

  As described above, the positions of a, b, c, d, e, and h of the shaped waveform S2 are specified. The inspiration time Ts and the expiration time Tb can be calculated from the following equations.

Inspiration time Ts = c time-a time Expiration time Tb = e time-d time Inspiration time Ts and expiration time Tb are obtained as described above. The above pattern recognition algorithm can be realized by, for example, sampling the shaped waveform S2 and executing a computer program.

  Returning to FIG. A1 to e3 of the shaped waveform S2 shown in this figure indicate the positions of the waveforms corresponding to the algorithm shown in FIG.

  FIG. 8 illustrates one embodiment. An apparatus 800 according to an embodiment of the present invention is placed beside the subject 100. A microwave is transmitted from the device 800, and the device 800 receives the microwave reflected from the subject 100. The device 800 is not necessarily placed in front of the chest, and can be measured in the vicinity of the subject to measure the expiration time and the inspiration time of the subject. Further, even if the device 800 is placed in a breast pocket or the like of the subject 100 and brought into contact with the subject 100 (not shown), the device 800 functions similarly.

  FIG. 9 illustrates the hardware configuration of one embodiment.

  Each of the plurality of components of each embodiment of the present invention can be realized by hardware, software, or a combination of hardware and software. Examples of hardware in which the present invention can be implemented include portable devices such as portable terminals, tablet terminals, laptop computers, and remote controls such as televisions. Other forms in which the present invention can be implemented may be incorporated in dedicated equipment that exclusively implements the present embodiment. Moreover, these apparatuses may be installed in specific places, such as a wall, and may be portable. Further, the present embodiment may be implemented in a wall-mounted clock, an alarm clock, a desk clock, a wristwatch, a wall-mounted thermometer, and the like. The embodiment of the present invention may be used in audio-visual distribution using a television or a computer, an interactive content program, or the like. Moreover, it cannot be overemphasized that the object of embodiment of this invention is not limited to a test subject, and living organisms, such as an animal which performs respiratory activity, may be sufficient.

  The apparatus according to an embodiment of the present invention may include a CPU 902, a ROM 904, a RAM 906, a record carrier interface 910, a display control unit 920, an input / output control unit 930, a communication interface 940, and a bus 950. Each component may be connected to each other by a bus 950. Other components may also be included.

  The record carrier interface 910 can read and write the memory card 912 storing the program and the like. Note that the recording medium is not limited to a memory card. The memory card 912 includes programs and data. The program stored in the memory card 912 can be executed by the CPU.

  The CPU can execute a program using programs and data stored in the ROM 904, the RAM 906, and the memory card 912.

  Note that the program of this embodiment can be stored in a record carrier such as the memory card 912. The storage medium including the memory card 912 refers to one or more non-transitory, tangible storage medium having a structure. Examples of portable recording media include magnetic recording media, optical discs, magneto-optical recording media, and nonvolatile memories. The memory card 912 includes various memory cards such as a USB memory and an SD memory card. Magnetic recording media include HDDs, flexible disks (FD), magnetic tapes (MT) and the like. Examples of the optical disk include a DVD (Digital Versatile Disc), a DVD-RAM, a CD-ROM (Compact Disc-Read Only Memory), and a CD-R (Recordable) / RW (ReWriteable). Magneto-optical recording media include MO (Magneto-Optical disk).

  The input / output control unit 930 exchanges data with, for example, the USB interface 932, the touch device 904, the keyboard 936, the audio input / output 938, and the like.

  The communication interface 940 may have an interface function with, for example, a WI-FI transceiver 942, a cellular phone transceiver 844, Bluetooth (registered trademark) 945, a microwave transmitter 946, and a microwave receiver 948. Various embodiments of the present invention include functions for transmitting and receiving microwaves. The microwave transmitter 946 and the microwave receiver 948 may use a dedicated interface that is separate from the communication interface 940. In addition, an existing wireless interface such as Bluetooth (registered trademark) 945 may be used for microwave transmission / reception. The various embodiments of the present invention are not limited to the use of microwaves, and electromagnetic waves in other bands such as millimeter waves may be used. What is necessary is just to prepare the transmitter / receiver according to the frequency of the electromagnetic waves used.

The following notes are disclosed regarding the above embodiment.
(Appendix 1)
A device for monitoring a living body,
In order to obtain a received signal, a receiving unit that receives electromagnetic waves reflected from a living body,
A feature extraction unit that extracts a plurality of features of the waveform of the received signal according to a predetermined pattern recognition rule;
An expiration / inspiration time estimation unit for estimating the expiration time and inspiration time of the living body based on the position on the time axis of the plurality of features;
An output unit for outputting the estimated exhalation time and the inhalation time;
Having a device.
(Appendix 2)
The feature extraction unit includes:
A waveform shaping unit that obtains a shaped waveform by applying an Nth derivative (N is an integer) to the received signal;
A feature recognition unit that recognizes the plurality of features by applying the predetermined pattern recognition rule to the shaped waveform;
The apparatus of claim 1 comprising:
(Appendix 3)
The feature extraction unit includes:
A signal period estimator for estimating a signal period including at least a breathing period from a signal of one frequency band among a plurality of frequency band signals included in the received signal;
Including
The estimated respiratory cycle is used to recognize the plurality of features.
The apparatus according to appendix 1 or 2.
(Appendix 4)
The signal period estimator is
A power spectrum converter for converting the received signal into a power spectrum;
A peak frequency specifying unit for specifying at least one peak frequency from the power spectrum;
A respiratory cycle estimator for estimating a respiratory cycle;
Including
The respiratory cycle estimator estimates the respiratory cycle based on the peak frequency;
The apparatus according to appendix 3.
(Appendix 5)
The signal period estimator is
A filter unit that extracts a filtered signal of a predetermined frequency band from the received signal according to the specified peak frequency,
The respiratory cycle estimation unit estimates the respiratory cycle based on the filtering signal.
The apparatus according to appendix 4.
(Appendix 6)
The signal period estimation unit is a heart rate information estimation unit that estimates information about a heart rate of a living body including a heart rate,
Further including
The apparatus according to any one of appendices 3 to 5, wherein the heartbeat information estimation unit provides information related to the heartbeat to the output unit.
(Appendix 7)
A control method for a device for monitoring a living body,
In order to obtain a received signal, the electromagnetic wave reflected from the living body is received,
Extracting a plurality of features of the waveform of the received signal according to a predetermined pattern recognition rule;
Based on the position of the plurality of features on the time axis, the expiration time and the inspiration time of the living body are estimated,
Outputting the estimated exhalation time and the inhalation time;
Control method with processing.
(Appendix 8)
The process of extracting the features includes:
Applying an Nth derivative (N is an integer) to the received signal to obtain a shaped waveform;
Applying the predetermined pattern recognition rule to the shaped waveform to recognize the plurality of features;
The control method according to appendix 7, including processing.
(Appendix 9)
The process of extracting the features includes:
Estimating a signal period including at least a respiratory cycle from a signal in one frequency band among a plurality of frequency band signals included in the received signal;
Including the processing, the estimated respiratory cycle is used to recognize the plurality of features;
The control method according to appendix 7 or 8.
(Appendix 10)
The process of estimating the signal period includes
Converting the received signal into a power spectrum;
Identifying at least one peak frequency from the power spectrum;
Estimating the respiratory cycle,
Including processing,
The process of estimating the respiratory cycle estimates the respiratory cycle based on the peak frequency.
The control method according to appendix 9.
(Appendix 11)
The process of estimating the signal period includes
Processing to extract a filtered signal of a predetermined frequency band from the received signal according to the specified peak frequency,
The process of estimating the respiratory cycle estimates the respiratory cycle based on the filtering signal.
The control method according to appendix 10.
(Appendix 12)
The process of estimating the signal period is a process of estimating information related to a heartbeat of a living body including a heart rate,
Further including
The control method according to any one of appendices 9 to 11, wherein the process of estimating information related to the heartbeat gives the information related to the heartbeat to the output process.
(Appendix 13)
A program for controlling a device for monitoring a living body by processing a reception signal received from an electromagnetic wave reflected from the living body,
In order to obtain a received signal, the electromagnetic wave reflected from the living body is received,
Extracting a plurality of features of the waveform of the received signal according to a predetermined pattern recognition rule;
Based on the position of the plurality of features on the time axis, the expiration time and the inspiration time of the living body are estimated,
Outputting the estimated exhalation time and the inhalation time;
A program that causes a computer to execute processing.
(Appendix 14)
The process of extracting the features includes:
Applying an Nth derivative (N is an integer) to the received signal to obtain a shaped waveform;
Applying the predetermined pattern recognition rule to the shaped waveform to recognize the plurality of features;
The program according to appendix 13, including processing.
(Appendix 15)
The process of extracting the features includes:
Estimating a signal period including at least a respiratory cycle from a signal in one frequency band among a plurality of frequency band signals included in the received signal;
Including the processing, the estimated respiratory cycle is used to recognize the plurality of features;
The program according to appendix 13 or 14.
(Appendix 16)
The process of estimating the signal period includes
Converting the received signal into a power spectrum;
Identifying at least one peak frequency from the power spectrum;
Estimating the respiratory cycle,
Including processing,
The process of estimating the respiratory cycle estimates the respiratory cycle based on the peak frequency.
The program according to appendix 15.
(Appendix 17)
The process of estimating the signal period includes
Processing to extract a filtered signal of a predetermined frequency band from the received signal according to the specified peak frequency,
The process of estimating the respiratory cycle estimates the respiratory cycle based on the filtering signal.
The program according to appendix 16.
(Appendix 18)
The process of estimating the signal period is a process of estimating information related to a heartbeat of a living body including a heart rate,
Further including
18. The program according to any one of appendices 15 to 17, wherein the process of estimating information relating to a heartbeat gives information relating to the heartbeat to the output process.

110 microwave transmission unit 112 transmission antenna 113 microwave 120 reception unit 122 reception antenna 130 feature extraction unit 132 waveform shaping unit 134 feature recognition unit 140 signal period estimation unit 142 power spectrum conversion unit 144 peak frequency identification unit 146 filter unit 148 heart rate information Estimator 149 Respiratory cycle estimator 150 Expiratory / inspiratory time estimator 160 Output unit

Claims (7)

A device for monitoring a living body,
In order to obtain a received signal, a receiving unit that receives electromagnetic waves reflected from a living body,
A feature extraction unit that extracts a plurality of features of the waveform of the received signal according to a predetermined pattern recognition rule;
An expiratory / inspiratory time estimating unit that estimates the expiratory time (Tb) and the inspiratory time (Ts) of the living body based on the positions of the plurality of features on the time axis;
An output unit for outputting the estimated exhalation time and the inhalation time;
Have
The feature extraction unit includes:
A signal period estimator for estimating a signal period including at least a respiratory period (T) from one frequency band signal among a plurality of frequency band signals included in the received signal;
Including
The estimated respiratory cycle (T) is
T> Tb + Tc
Used to recognize the plurality of features,
apparatus. The feature extraction unit includes:
A waveform shaping unit that obtains a shaped waveform by applying an Nth derivative (N is an integer) to the received signal;
A feature recognition unit that recognizes the plurality of features by applying the predetermined pattern recognition rule to the shaped waveform;
The apparatus of claim 1, comprising: The signal period estimator is
A power spectrum converter for converting the received signal into a power spectrum;
A peak frequency specifying unit for specifying at least one peak frequency from the power spectrum;
A respiratory cycle estimator for estimating a respiratory cycle;
Including
The respiratory cycle estimator estimates the respiratory cycle based on the peak frequency;
The apparatus according to claim 1 or 2 . The signal period estimator is
A filter unit that extracts a filtered signal of a predetermined frequency band from the received signal according to the specified peak frequency,
The respiratory cycle estimation unit estimates the respiratory cycle based on the filtering signal.
The apparatus according to claim 3 . The signal period estimation unit is a heart rate information estimation unit that estimates information about a heart rate of a living body including a heart rate,
Further including
The apparatus according to any one of claims 1 to 4 , wherein the heartbeat information estimation unit provides information related to the heartbeat to the output unit. A control method for a device for monitoring a living body,
In order to obtain a received signal, the electromagnetic wave reflected from the living body is received,
Extracting a plurality of features of the waveform of the received signal according to a predetermined pattern recognition rule;
Based on the position of the plurality of features on the time axis, the expiration time (Tb) and the inspiration time (Ts) of the living body are estimated,
Outputting the estimated exhalation time and the inhalation time;
Have processing,
The process of extracting the features includes:
A process of estimating a signal period, estimating a signal period including at least a breathing period (T) from a signal of one frequency band among a plurality of frequency band signals included in the received signal;
Including
The estimated respiratory cycle (T) is
T> Tb + Tc
Used to recognize the plurality of features,
Control method. A program for controlling a device for monitoring a living body by processing a reception signal received from an electromagnetic wave reflected from the living body,
In order to obtain a received signal, the electromagnetic wave reflected from the living body is received,
Extracting a plurality of features of the waveform of the received signal according to a predetermined pattern recognition rule;
Based on the position of the plurality of features on the time axis, the expiration time (Tb) and the inspiration time (Ts) of the living body are estimated,
Outputting the estimated exhalation time and the inhalation time;
A program for executing the process to the computer,
The process of extracting the features includes:
A process of estimating a signal period, estimating a signal period including at least a breathing period (T) from a signal of one frequency band among a plurality of frequency band signals included in the received signal;
Including
The estimated respiratory cycle (T) is
T> Tb + Tc
Used to recognize the plurality of features,
Program .

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