CN108652601B - Sleep monitoring method and device based on frequency modulation continuous wave millimeter wave radar and radar system - Google Patents

Sleep monitoring method and device based on frequency modulation continuous wave millimeter wave radar and radar system Download PDF

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CN108652601B
CN108652601B CN201810504806.2A CN201810504806A CN108652601B CN 108652601 B CN108652601 B CN 108652601B CN 201810504806 A CN201810504806 A CN 201810504806A CN 108652601 B CN108652601 B CN 108652601B
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target person
spectrum
target
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CN108652601A (en
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张谅
赵铁刚
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Xiamen Jingyi Yuanda Intelligent Technology Co ltd
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Xiamen Jingyi Yuanda Intelligent Technology Co ltd
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/0205—Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7235—Details of waveform analysis
    • A61B5/725—Details of waveform analysis using specific filters therefor, e.g. Kalman or adaptive filters
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7235—Details of waveform analysis
    • A61B5/7253—Details of waveform analysis characterised by using transforms
    • A61B5/7257—Details of waveform analysis characterised by using transforms using Fourier transforms
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/74—Details of notification to user or communication with user or patient ; user input means
    • A61B5/746—Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024—Detecting, measuring or recording pulse rate or heart rate
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/08—Detecting, measuring or recording devices for evaluating the respiratory organs
    • A61B5/0816—Measuring devices for examining respiratory frequency
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
    • A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
    • A61B5/1116—Determining posture transitions

Abstract

The invention provides a sleep monitoring method, a sleep monitoring device and a sleep monitoring radar system based on a frequency modulation continuous wave millimeter wave radar. Respectively mixing the first reflection signal and the second reflection signal with a local oscillation signal to obtain a first mixing signal and a second mixing signal; the local oscillator signal is a signal which is generated by the frequency modulation continuous wave millimeter wave radar at the same frequency as the transmitted signal at one moment. And acquiring the breathing frequency, the heartbeat frequency and the turn-over information of the target person according to the first mixing signal and the second mixing signal. The invention extracts the detection signal by mixing the sending signal and the receiving signal, has simple circuit design, less hardware consumption resources and cost saving.

Description

Sleep monitoring method and device based on frequency modulation continuous wave millimeter wave radar and radar system
Technical Field
The invention relates to the technical field of information communication, in particular to a sleep monitoring method and device based on a frequency modulation continuous wave millimeter wave radar and a radar system.
Background
With the acceleration of life rhythm, people's life pressure is bigger and bigger, and more people are in sub-health state, and the insomnia crowd is gradually increased. Meanwhile, with the increasingly prominent social aging problem, more and more empty nesters have more and more health problems, especially chronic diseases such as cardiovascular and cerebrovascular diseases and paroxysmal diseases. Therefore, how to monitor health indexes such as respiration and heartbeat of a human body in real time in an indoor environment and how to determine whether the human body enters deep sleep or not becomes a problem to be considered in terms of human health. Currently, many products have been detecting health information of human body indoors through lighting devices embedded with radar. Some existing detection methods simply judge echo information received by a radar. Some detection methods extract the detection signal by using a standing wave form, i.e. the frequency of the transmitted and received signals is required to be identical. Some detection methods require the use of two fixed-distance power detectors during detection. Some detection methods need to judge through phase angle changes when detecting small displacements.
The problems existing in the prior art are as follows:
1. the method has the advantages that the echo information received by the radar is simply judged, the decision method is rough, and the detection precision of human breath and heartbeat is poor.
2. The detection signal is extracted in the form of standing wave, i.e. the frequency of the transmitted and received signal is required to be identical, so that the requirement on the frequency stability of the signal is high.
3. Two power detectors with fixed distance are needed for detection, so that distance accuracy is required, and more resources are consumed.
4. When the micro displacement is detected, the judgment needs to be carried out through the phase angle change, so that the requirement on the phase angle measurement precision is high.
Disclosure of Invention
The sleep monitoring method, the sleep monitoring device and the radar system based on the frequency modulation continuous wave millimeter wave radar have the real-time detection function and improve the detection accuracy.
In a first aspect, an embodiment of the present invention provides a sleep monitoring method based on a frequency modulated continuous wave millimeter wave radar, which specifically includes:
collecting a first reflection signal of a target space in an unmanned state and a second reflection signal of the target space in a manned state by a frequency modulation continuous wave millimeter wave radar;
respectively mixing the first reflection signal and the second reflection signal with a local oscillation signal to obtain a first mixing signal and a second mixing signal; the local oscillator signal is a signal which is generated by the frequency modulation continuous wave millimeter wave radar at a moment and has the same frequency as the transmitted signal;
and acquiring the breathing frequency, the heartbeat frequency and the turn-over information of the target person according to the first mixing signal and the second mixing signal.
Further, the step of obtaining the breathing frequency and the heartbeat frequency of the target person according to the first mixing signal and the second mixing signal includes:
extracting difference frequency signals of the first mixing signal and the second mixing signal from a low-pass filter respectively;
performing FFT spectrum analysis on a difference frequency signal of the first mixing signal of the target space, and recording complete spectrum information of the target space as a spectrum initial value Sa 1;
performing FFT spectrum analysis on the difference frequency signal of the second mixing signal of the target space, and recording complete spectrum information of the target space and the target person as a spectrum value Sa 2;
extracting frequency spectrum information Sa of a target person, and recording the maximum peak frequency f0 of amplitude-frequency characteristics of the frequency spectrum information Sa, wherein Sa is Sa 2-Sa 1;
performing fast Fourier transform on the amplitude-frequency and phase-frequency information at the maximum peak frequency f0 to obtain an amplitude frequency spectrum Sv, solving the speed information of the object at the distance corresponding to the maximum peak frequency f0, and obtaining a respiratory rate spectral line f1 and a heartbeat rate spectral line f2 of the target person;
recording a time interval delta t1 between two starting moments of the breathing speed spectral line f1 of the target person, and calculating the breathing frequency of the target person to be 1/delta t 1;
the time interval Δ t2 between the start times of the heartbeat velocity spectrum f2 of the target person is recorded twice, and the target person heartbeat frequency 1/Δ t2 is obtained.
Further, the respiration rate line and the heartbeat rate line are both peak lines of the amplitude spectrum Sv and f1< f 2.
Further, the step of acquiring the turning information of the target person comprises:
detecting whether a third peak spectral line f3 other than f1 and f2 exists in the amplitude spectrum Sv;
if yes, judging whether f1< f2< f3 is met;
if yes, judging that the turning information of the target person appears.
Furthermore, the frequency modulation continuous wave millimeter wave radar is arranged on the ceiling of the indoor space or on a high wall to monitor the sleep of the target person in the indoor space.
Further, when the breathing frequency or the heartbeat frequency of the target person is at a preset danger threshold, generating an alarm message; the alarm message is sent to the user terminal associated with the frequency modulated continuous wave millimeter wave radar through wireless communication.
Further, when two target figures exist in the target space, judging that the distance difference between the frequency modulation continuous wave millimeter wave radar and the two target figures is larger than the distance resolution L; if so, acquiring respiratory frequency, heartbeat frequency and turning-over information corresponding to the two target figures; wherein, L is c/2B.
In a second aspect, an embodiment of the present invention provides a sleep monitoring apparatus based on a frequency modulated continuous wave millimeter wave radar, including a processor, specifically including:
and the signal acquisition module is used for acquiring a first reflection signal of the target space in an unmanned state and a second reflection signal of the target space in a manned state through the frequency modulation continuous wave millimeter wave radar.
The frequency mixing signal module is used for respectively mixing the first reflection signal and the second reflection signal with a local oscillator signal to obtain a first frequency mixing signal and a second frequency mixing signal; the local oscillator signal is a signal which is generated by the frequency modulation continuous wave millimeter wave radar at the same frequency as the transmitted signal at one moment.
And the data extraction module is used for acquiring the respiratory frequency, the heartbeat frequency and the turning-over information of the target person according to the first mixing signal and the second mixing signal.
The data extraction module is further configured to:
the difference frequency signals of the first mixing signal and the second mixing signal are extracted from the low pass filter, respectively.
And performing FFT spectrum analysis on the difference frequency signal of the first mixing signal of the target space, and recording complete spectrum information of the target space as a spectrum initial value Sa 1.
And performing FFT spectrum analysis on the difference frequency signal of the second mixing signal of the target space, and recording complete spectrum information of the target space and the target person as a spectrum value Sa 2.
Extracting the frequency spectrum information Sa of the target person, and recording the maximum peak frequency f0 of amplitude-frequency characteristics of the frequency spectrum information Sa, wherein Sa is Sa 2-Sa 1.
Performing fast Fourier transform on amplitude-frequency and phase-frequency information at the maximum peak frequency f0 to obtain an amplitude frequency spectrum Sv, solving speed information of an object at a distance corresponding to the maximum peak frequency f0, and obtaining a breathing speed spectral line f1 and a heartbeat speed spectral line f2 of a target person; wherein, the respiratory velocity spectral line and the heartbeat velocity spectral line are both peak spectral lines of the amplitude spectrum Sv, and f1 is less than f 2.
The time interval delta t1 between the starting times of the breathing rate spectral lines f1 appearing twice by the target person is recorded, and the breathing frequency of the target person is found to be 1/delta t 1.
And recording the time interval delta t2 between the two times of starting moments of the heartbeat velocity spectral line f2 of the target person, and obtaining the heartbeat frequency 1/delta t2 of the target person.
The judging module is used for detecting whether the amplitude spectrum Sv has a third peak spectral line f3 except for f1 and f 2;
if yes, judging whether f1< f2< f3 is met;
if yes, judging that the turning information of the target person appears.
And the monitoring module is used for arranging the frequency modulation continuous wave millimeter wave radar on a ceiling or a high-altitude wall of the indoor space and monitoring the sleep of the target person in the indoor space.
The alarm generating and sending module is used for generating an alarm message when the breathing frequency or the heartbeat frequency of the target person is at a preset danger threshold; and sending the alarm message to the user terminal associated with the frequency modulation continuous wave millimeter wave radar through wireless communication.
In a third aspect, an embodiment of the present invention provides a sleep monitoring system based on a frequency modulated continuous wave millimeter wave radar, including a receiving and transmitting antenna, a peripheral circuit, a frequency modulated continuous wave millimeter wave radar sensor, a wireless module, and a processor, where the processor executes the method according to the first aspect of the embodiment of the present invention.
The embodiment of the invention has the following beneficial effects:
according to the sleep monitoring method and device based on the frequency modulation continuous wave millimeter wave radar and the radar system, the detection signal is extracted in a mode of mixing the transmitting signal and the receiving signal, the circuit design is simple, the hardware consumption resource is less, and the cost is saved.
The detection signal of the invention mainly extracts the frequency difference of the receiving and transmitting signal, does not require the frequency of the receiving and transmitting signal to be completely consistent, and extracts the speed peak value information by carrying out fast Fourier transform on a plurality of sweep frequency bands when judging the respiratory frequency and the heartbeat of a human body, thereby having certain tolerance to the frequency stability and the phase angle precision of the signal and having high measurement precision.
The invention can simultaneously detect the respiratory frequency, the heartbeat frequency, the turnover condition and other information of two or more people, thereby realizing the sleep monitoring of the multiple people.
The invention can detect the chronic diseases, the paroxysmal diseases and the paroxysmal conditions of the human body by combining different application scenes and different health index standards on the basis of detecting the respiratory frequency, the heartbeat and the turn-over statistical conditions of the human body. Thus, by expanding the method of the present invention, a variety of different functions can be achieved.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic flowchart of an embodiment of a sleep monitoring method based on a frequency modulated continuous wave millimeter wave radar according to the present invention.
FIG. 2 is a flow chart illustrating an embodiment of a data acquisition method provided by the present invention.
Fig. 3 is a schematic flow chart of the turning information judgment provided by the present invention.
Fig. 4 is a schematic structural diagram of a sleep monitoring device based on a frequency modulated continuous wave millimeter wave radar provided by the invention.
Fig. 5 is a spectrum Sv provided by the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The first embodiment of the present invention:
referring to fig. 1 to fig. 3, fig. 1 is a schematic flowchart of an embodiment of a sleep monitoring method based on a frequency modulated continuous wave millimeter wave radar according to the present invention. FIG. 2 is a flow chart illustrating an embodiment of a data acquisition method provided by the present invention. Fig. 3 is a schematic flow chart of the turning information judgment provided by the present invention. The invention provides a sleep monitoring method based on a frequency modulation continuous wave millimeter wave radar, which can realize a radar monitoring module and is applied to various common household equipment, and the application environment can be various indoor scenes such as bedrooms, kitchens, bathrooms and the like. On the basis of the method, the respiratory frequency, the heartbeat and the like can be compared with the normal indexes of the human body, so that the health condition of the human body can be detected in real time, meanwhile, the sudden conditions of the human body, such as asphyxia, heartbeat stop and the like can be detected in time, and the alarm processing can be carried out in time through a wireless module or other communication methods. The embodiment of the invention provides a sleep monitoring method based on a frequency modulation continuous wave millimeter wave radar, which specifically comprises the following steps:
and S10, collecting a first reflected signal of the target space in the unmanned state and a second reflected signal of the target space in the manned state by using a frequency modulation continuous wave millimeter wave radar.
The frequency modulation continuous wave millimeter wave radar is arranged on a ceiling of an indoor space or a high-altitude wall, the frequency modulation continuous wave millimeter wave radar transmits frequency modulation continuous waves outwards through a transmitting antenna, the frequency modulation continuous wave millimeter wave radar is called as a transmitting signal, electromagnetic waves transmitted to a target to be detected can generate reflecting signals respectively through a target space in an unmanned state and a target space in a manned state, and the two groups of reflecting signals are called as receiving signals (or echo signals and reflecting signals) through receiving antennas of the frequency modulation continuous wave millimeter wave radar, so that the two groups of reflecting signals enter a subsequent signal processing circuit connected with the frequency modulation continuous wave millimeter wave radar. Millimeter wave (millimeter wave) is used in the millimeter wave radar, generally, the millimeter wave refers to a frequency domain (wavelength is 1-10 mm) of 30-300 GHz, and the millimeter wave is an electromagnetic wave between an infrared light wave and a microwave frequency band.
And S20, respectively mixing the first reflection signal and the second reflection signal with the local oscillation signal to obtain a first mixing signal and a second mixing signal.
The frequency mixing operation is completed by a frequency mixer of the circuit, and is actually a signal multiplier, namely, the multiplication operation is performed on two paths of signals at two input ends of the frequency mixer, wherein the two paths of signals are respectively a reflected signal received by the radar and a local oscillator signal. The local oscillator signal is a signal which is generated by the radar circuit and has the same frequency with the transmitting signal at one moment, and is generated by the local oscillator.
And S30, acquiring the breathing frequency, the heartbeat frequency and the turn-over information of the target person according to the first mixing signal and the second mixing signal.
In this embodiment, after receiving the first reflected signal and the second reflected signal, the fm-cw millimeter wave radar may analyze the first reflected signal and the second reflected signal to obtain at least information such as a position, a moving speed, and frequency spectrum information of the target person, and calculate a breathing frequency, a heartbeat frequency, and turn-over information of the target person according to the information to monitor sleep of the target person. More specifically, referring to fig. 2 and 3, the acquiring of the breathing frequency, the heartbeat frequency and the turning over of the target person may include:
s31, difference signals of the first mixed signal and the second mixed signal are extracted from the low-pass filter, respectively.
S32, performing FFT spectrum analysis on the difference frequency signal of the first mixing signal of the target space, and recording complete spectrum information of the target space as a spectrum initial value Sa 1.
S33, performing FFT spectrum analysis on the difference frequency signal of the second mixing signal of the target space, and recording complete spectrum information of the target space and the target person as a spectrum value Sa 2.
A low-pass filter is an electronic filtering device that allows signals below a cutoff frequency to pass, but does not allow signals above the cutoff frequency to pass.
The spectrum analysis, namely, the time domain information of the signal is observed and analyzed through the frequency domain characteristic, usually adopt FFT (fast Fourier transform), that is, fast Fourier transform, which is a fast algorithm of discrete Fourier transform, and it is obtained by improving the algorithm of discrete Fourier transform according to the characteristics of odd, even, imaginary, real, etc. of the discrete Fourier transform, the FFT operation formula is as follows:
Figure GDA0002756868560000081
Figure GDA0002756868560000082
wherein the content of the first and second substances,
Figure GDA0002756868560000083
if the frequency spectrum diagram is used for representation, the abscissa of the frequency spectrum diagram is a frequency value, the ordinate of the frequency spectrum diagram is an amplitude value corresponding to different frequency points, the amplitude can represent the energy of the signal under the frequency, so that the frequency spectrum diagram can be seen to have different amplitudes under different frequencies, the amplitude spectrum of the amplitude of the difference frequency signal is higher than other frequency points, the amplitudes corresponding to other frequency points are noise signals of the surrounding environment, and the time and the frequency at the moment are determined by searching for the maximum value in the frequency spectrum.
And S34, extracting the frequency spectrum information Sa of the target person, and recording the maximum peak frequency f0 of amplitude-frequency characteristics of the frequency spectrum information Sa, wherein Sa is Sa 2-Sa 1.
S35, performing fast Fourier transform on the amplitude frequency and phase frequency information at the maximum peak frequency f0 to obtain an amplitude frequency spectrum Sv, solving the speed information of the object at the distance corresponding to the maximum peak frequency f0, and obtaining a breathing speed spectral line f1 and a heartbeat speed spectral line f2 of the target person.
The respiratory velocity line and the heartbeat velocity line are both peak lines of the amplitude spectrum Sv and f1<f2. The formula for calculating the velocity from the spectrogram Sv is:
Figure GDA0002756868560000091
wherein f isdRepresenting the frequency corresponding to the peak line in the spectrum, fcRepresenting the carrier frequency, c represents the speed of electromagnetic wave propagation.
And S36, recording the time interval delta t1 between the starting moments of the breathing speed spectral lines f1 of the target person appearing twice, and obtaining the breathing frequency of the target person to be 1/delta t 1.
And S37, recording the time interval delta t2 between the starting moments of the heartbeat velocity spectral lines f2 of the target person twice, and obtaining the heartbeat frequency 1/delta t2 of the target person.
A32, detecting whether the amplitude spectrum Sv has a third peak spectral line f3 except f1 and f 2;
a33, if yes, judging whether f1< f2< f3 is satisfied;
and A34, if yes, judging that the turning information of the target person appears.
With particular reference to fig. 5, the abscissa represents frequency and the ordinate represents amplitude.
Whether the respiration line f1, the heartbeat line f2 or the turnover information line f3 are peaks near the spectrogram, for example, the peak value at 35000 shown in fig. 5 is f3,17000, the peak value at f2,15000 is f 1. By setting a turnover information spectral line threshold 25000, a breathing frequency spectrum, a heartbeat frequency spectrum and a turnover information spectral line are sequentially determined according to the frequency of the frequency spectrum exceeding the threshold.
The frequency modulation continuous wave millimeter wave radar can also monitor the breathing frequency, the heartbeat frequency and the turning-over information of two target figures.
When two target figures exist in the target space, judging that the distance difference between the frequency modulation continuous wave millimeter wave radar and the two target figures is larger than the distance resolution L; and if so, acquiring the respiratory frequency, the heartbeat frequency and the turning-over information corresponding to the two target figures.
Selecting a proper installation position (high on a side wall or a side ceiling), ensuring that the distance difference between two target persons to be detected and the frequency modulation continuous wave millimeter wave radar is larger than a certain value L (the value can be calculated by a formula, wherein L is c/2B, c represents the propagation speed of electromagnetic waves in vacuum, B represents the bandwidth of a transmitted signal, for example, the frequency modulation continuous wave radar of 24GHz, and when the bandwidth of the transmitted signal is 250MHz, the value of L is 60cm), and realizing the detection of a plurality of target persons by utilizing a plurality of pieces of peak value information of a detection signal spectrum through the steps.
Second embodiment of the invention:
on the basis of the first embodiment of the present invention, the second embodiment of the present invention may notify the user terminal associated with the fm continuous wave millimeter wave radar through network connection when the respiratory frequency or the heartbeat frequency of the target person is at a preset danger threshold, so that the associated user terminal can immediately know that the target person is abnormal, and the worse result is prevented. It will be appreciated that the network connection may be a wired network connection or a wireless network connection. And are not limited herein. In some cases, the alarm module can be arranged, so that when the monitored object is judged to fall down, an alarm is given immediately, for example, a buzzer or other sounds are given, and the monitored object is reminded to quickly react with people in a room.
The embodiment of the invention can also obtain the maximum peak frequency f0 according to the formula S ═ c · f0 · Tw/2·BwCalculating to obtain the distance S of the human body relative to the radar, wherein c is the propagation speed of the electromagnetic wave in the air, and BwFor swept bandwidth of the signal, TwIs the sweep time of the signal. Whether the target figure is in an abnormal position or not can be obtained by comparing the distance of the bed, the bathtub and the like relative to the radar in an indoor scene with the S, and whether the human body is in a falling or other disease emergency or not is judged by combining the information of the respiratory frequency, the heartbeat frequency and the like of the target figure, so that the timely alarm processing is carried out.
Third embodiment of the invention:
on the basis of the first embodiment, referring to fig. 3, fig. 3 is a schematic structural diagram of a fall monitoring device based on a frequency modulated continuous wave millimeter wave radar according to the present invention. A third embodiment of the present invention provides a fall monitoring device based on a frequency modulated continuous wave millimeter wave radar, including a processor, the processor including:
and the signal acquisition module 10 is configured to acquire a first reflection signal of the target space in an unmanned state and a second reflection signal of the target space in a manned state through the frequency modulation continuous wave millimeter wave radar.
A frequency mixing signal module 20, configured to respectively perform frequency mixing on the first reflected signal and the second reflected signal with a local oscillator signal to obtain a first frequency mixing signal and a second frequency mixing signal; the local oscillator signal is a signal which is generated by the frequency modulation continuous wave millimeter wave radar at the same frequency as the transmitted signal at one moment.
And the data extraction module 30 is configured to obtain the breathing frequency, the heartbeat frequency and the turning information of the target person according to the first mixing signal and the second mixing signal.
The data extraction module is further configured to:
the difference frequency signals of the first mixing signal and the second mixing signal are extracted from the low pass filter, respectively.
And performing FFT spectrum analysis on the difference frequency signal of the first mixing signal of the target space, and recording complete spectrum information of the target space as a spectrum initial value Sa 1.
And performing FFT spectrum analysis on the difference frequency signal of the second mixing signal of the target space, and recording complete spectrum information of the target space and the target person as a spectrum value Sa 2.
Extracting the frequency spectrum information Sa of the target person, and recording the maximum peak frequency f0 of amplitude-frequency characteristics of the frequency spectrum information Sa, wherein Sa is Sa 2-Sa 1.
Performing fast Fourier transform on amplitude-frequency and phase-frequency information at the maximum peak frequency f0 to obtain an amplitude frequency spectrum Sv, solving speed information of an object at a distance corresponding to the maximum peak frequency f0, and obtaining a breathing speed spectral line f1 and a heartbeat speed spectral line f2 of a target person; wherein, the respiratory velocity spectral line and the heartbeat velocity spectral line are both peak spectral lines of the amplitude spectrum Sv, and f1 is less than f 2.
The time interval delta t1 between the starting times of the breathing rate spectral lines f1 appearing twice by the target person is recorded, and the breathing frequency of the target person is found to be 1/delta t 1.
And recording the time interval delta t2 between the two times of starting moments of the heartbeat velocity spectral line f2 of the target person, and obtaining the heartbeat frequency 1/delta t2 of the target person.
The judging module 40 is configured to detect whether the amplitude spectrum Sv has a third peak spectral line f3 outside f1 and f 2;
if yes, judging whether f1< f2< f3 is met;
if yes, judging that the turning information of the target person appears.
And the monitoring module 50 is used for arranging the frequency modulation continuous wave millimeter wave radar on the ceiling of the indoor space or at the high position of the side wall to monitor the sleep of the target person in the indoor space.
The alarm generating and sending module 60 generates an alarm message when the breathing frequency or the heartbeat frequency of the target person is at a preset danger threshold; and sending the alarm message to the user terminal associated with the frequency modulation continuous wave millimeter wave radar through wireless communication.
Adult breaths at 16-20 per minute, and elderly usually breathe at a rate of over 24 breaths/min, called hyperpnea, and less than 12 breaths/min, called bradycardia, which are abnormal conditions set as risk thresholds.
The heartbeat refers to the number of heartbeats per minute in a quiet state of a normal person, also called quiet heartbeat, and is generally 60-100 beats/minute, more than 120 beats/minute and less than 50 beats/minute, which are abnormal states and are set as a danger threshold.
The Wireless Communication may be, for example, wirelessly connected to a user terminal associated with the fm-cw radar through internet (including cloud services), bluetooth Communication, Near field Communication (FFC), or Wireless Fidelity (WIFI) Communication, and the user terminal monitors the condition of the monitored object through a smart phone, a Personal Digital Assistant (PAD), a pda phone, a tablet computer, and a PC.
A fourth embodiment of the present invention provides a monitoring system based on frequency modulated continuous wave millimeter wave radar, comprising a receiving and transmitting antenna, a peripheral circuit, a frequency modulated continuous wave millimeter wave radar sensor, and a processor, wherein the processor executes the method as described in the first embodiment or the second embodiment, for example, step S10 shown in fig. 1.
The receiving antenna and the transmitting antenna are antennas for sending and receiving electromagnetic waves, and the peripheral circuit is a circuit which is set up at the periphery of the frequency modulation continuous wave millimeter wave radar sensor and used for detecting the falling condition of a human body.
The frequency modulation continuous wave millimeter wave radar sensor adopted by the embodiment adopts: frequency modulated continuous wave radar sensor: and selecting 24GHz as a transmitting frequency, and calculating the moving speed of the object by using the frequency difference between the transmitting signal and the receiving signal through a formula. Through the frequency mixing of the reference signal and the echo signal, the moving direction (far away or close) of the object can be identified according to the positive and negative of the frequency of the peak spectral line through the spectrum analysis of the two-dimensional FFT of the frequency mixing signal. FMCW radar sensor: if a parameter [ distance ] is to be measured, such as the distance of a static object from the sensor, it is sufficient to use a linear ramp-up or ramp-down as a time-dependent function of the transmit frequency, and to repeat these ramps periodically in order to obtain a possible average value. The distance of the object can be obtained according to a calculation formula of the delay effect.
It should be noted that, each module of the processor disclosed in this embodiment may be implemented by hardware, and examples of the processor may be an X86-based processor, a Reduced Instruction Set Computing (RISC) processor, an Application Specific Integrated Circuit (ASIC) processor, a Complex Instruction Set Computing (CISC) processor, a Central Processing Unit (CPU), a display parallel instruction computing (EPIC) processor, a Very Long Instruction Word (VLIW) processor, and/or other processors of a circuit, which are not described herein again.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (7)

1. A sleep monitoring method based on a frequency modulation continuous wave millimeter wave radar is characterized by comprising the following steps:
collecting a first reflection signal of a target space in an unmanned state and a second reflection signal of the target space in a manned state by a frequency modulation continuous wave millimeter wave radar;
respectively mixing the first reflection signal and the second reflection signal with a local oscillation signal to obtain a first mixing signal and a second mixing signal; the local oscillator signal is a signal which is generated by the frequency modulation continuous wave millimeter wave radar at the moment and has the same frequency as the transmitted signal;
acquiring the breathing frequency, the heartbeat frequency and the turning-over information of the target person according to the first mixing signal and the second mixing signal; the method comprises the following steps:
extracting difference frequency signals of the first mixing signal and the second mixing signal from the low-pass filter respectively;
performing FFT spectrum analysis on a difference frequency signal of the first mixing signal of the target space, and recording complete spectrum information of the target space as a spectrum initial value Sa 1;
performing FFT spectrum analysis on the difference frequency signal of the second mixing signal of the target space, and recording complete spectrum information of the target space and the target person as a spectrum value Sa 2;
extracting frequency spectrum information Sa of the target person, and recording the maximum peak frequency f0 of amplitude-frequency characteristics of the frequency spectrum information Sa, wherein Sa is Sa 2-Sa 1;
performing fast fourier transform on the amplitude-frequency and phase-frequency information at the maximum peak frequency f0 to obtain an amplitude frequency spectrum Sv, solving the speed information of the object at the distance corresponding to the maximum peak frequency f0, and obtaining a respiratory rate spectral line f1 and a heartbeat rate spectral line f2 of the target person;
recording a time interval delta t1 between the starting moments of the breathing speed spectral lines f1 of the target person appearing twice, and calculating the breathing frequency of the target person to be 1/delta t 1;
recording a time interval delta t2 between the starting moments of the heartbeat velocity spectral line f2 of the target person twice, and calculating the heartbeat frequency 1/delta t2 of the target person;
detecting whether a third peak spectral line f3 other than f1 and f2 exists in the amplitude spectrum Sv;
if yes, judging whether f1< f2< f3 is met;
if yes, judging that the turning information of the target person appears.
2. The method as claimed in claim 1, wherein the respiratory rate spectral line and the heartbeat rate spectral line are both peak spectral lines of the amplitude spectrum Sv and f1< f 2.
3. The frequency modulated continuous wave millimeter wave radar-based sleep monitoring method according to claim 1, wherein the frequency modulated continuous wave millimeter wave radar is installed on a ceiling or a high wall of an indoor space to monitor the sleep of the target person in the indoor space.
4. The sleep monitoring method based on frequency modulated continuous wave millimeter wave radar as claimed in claim 1, wherein when the breathing frequency or the heartbeat frequency of the target person is at a preset danger threshold, an alarm message is generated; and the alarm message is sent to the user terminal associated with the frequency modulation continuous wave millimeter wave radar through wireless communication.
5. The frequency modulated continuous wave millimeter wave radar-based sleep monitoring method according to claim 3, wherein when two target persons exist in the target space, it is determined whether a distance difference between the frequency modulated continuous wave millimeter wave radar and the two target persons is greater than a distance resolution L; if so, acquiring respiratory frequency, heartbeat frequency and turning-over information corresponding to the two target figures; wherein, L is c/2B; c represents the propagation speed of the electromagnetic wave in vacuum, and B represents the bandwidth of the transmitted signal.
6. A sleep monitoring device based on frequency modulation continuous wave millimeter wave radar, includes the treater, its characterized in that, the treater includes:
the signal acquisition module is used for acquiring a first reflection signal of a target space in an unmanned state and a second reflection signal of the target space in a manned state through a frequency modulation continuous wave millimeter wave radar;
the frequency mixing signal module is used for respectively mixing the first reflection signal and the second reflection signal with a local oscillator signal to obtain a first frequency mixing signal and a second frequency mixing signal; the local oscillator signal is a signal which is generated by the frequency modulation continuous wave millimeter wave radar at the moment and has the same frequency as the transmitted signal;
the data extraction module is used for acquiring the breathing frequency, the heartbeat frequency and the turning-over information of the target person according to the first mixing signal and the second mixing signal;
the data extraction module is further configured to:
extracting difference frequency signals of the first mixing signal and the second mixing signal from a low-pass filter respectively;
performing FFT spectrum analysis on a difference frequency signal of the first mixing signal of the target space, and recording complete spectrum information of the target space as a spectrum initial value Sa 1;
performing FFT spectrum analysis on the difference frequency signal of the second mixing signal of the target space, and recording complete spectrum information of the target space and the target person as a spectrum value Sa 2;
extracting frequency spectrum information Sa of the target person, and recording the maximum peak frequency f0 of amplitude-frequency characteristics of the frequency spectrum information Sa, wherein Sa is Sa 2-Sa 1;
performing fast fourier transform on the amplitude-frequency and phase-frequency information at the maximum peak frequency f0 to obtain an amplitude frequency spectrum Sv, solving the speed information of the object at the distance corresponding to the maximum peak frequency f0, and obtaining a respiratory rate spectral line f1 and a heartbeat rate spectral line f2 of the target person; wherein the respiration rate spectral line and the heartbeat rate spectral line are both peak spectral lines of the amplitude spectrum Sv and f1< f 2;
recording a time interval delta t1 between the starting moments of the breathing speed spectral lines f1 of the target person appearing twice, and calculating the breathing frequency of the target person to be 1/delta t 1;
recording a time interval delta t2 between the starting moments of the heartbeat velocity spectral line f2 of the target person twice, and calculating the heartbeat frequency 1/delta t2 of the target person;
a judging module, configured to detect whether there is a third peak spectral line f3 outside f1 and f2 in the amplitude spectrum Sv;
if yes, judging whether f1< f2< f3 is met;
if yes, judging that the turning-over information of the target figure appears;
the monitoring module is used for arranging the frequency modulation continuous wave millimeter wave radar on a ceiling or a high-altitude wall of an indoor space and monitoring the sleep of the target person in the indoor space;
the alarm generating and sending module is used for generating an alarm message when the respiratory frequency or the heartbeat frequency of the target person is at a preset danger threshold; and the alarm message is sent to the user terminal associated with the frequency modulation continuous wave millimeter wave radar through wireless communication.
7. A frequency modulated continuous wave millimeter wave radar system, comprising:
the device comprises a radar, a receiving antenna, a transmitting antenna, a peripheral circuit, a wireless module and a processor; the processor performs the sleep monitoring method as claimed in any one of claims 1 to 5.
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Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109512414B (en) * 2018-11-10 2021-12-31 临海楠竹电子科技有限公司 Basic vital sign data acquisition system and heart rate detection system applying same
CN109480787B (en) * 2018-12-29 2021-06-25 中国科学院合肥物质科学研究院 Non-contact sleep monitoring equipment based on ultra-wideband radar and sleep staging method
CN109729632B (en) * 2018-12-29 2021-05-28 深圳市铂越科技有限公司 Lighting lamp and control method thereof
CN109814102B (en) * 2019-01-31 2020-10-27 厦门精益远达智能科技有限公司 Single lane superelevation monitoring method, device, equipment and storage medium
CN109615882A (en) * 2019-01-31 2019-04-12 厦门精益远达智能科技有限公司 A kind of one-lane statistical method of traffic flow, device, equipment and storage medium
CN111751814A (en) * 2019-03-29 2020-10-09 富士通株式会社 Motion state detection device, method and system based on wireless signals
CN109917374A (en) * 2019-04-01 2019-06-21 深圳乐易住智能科技股份有限公司 A kind of indoor detection method using Distributed Network Radar
CN110150926B (en) * 2019-07-09 2021-01-22 京东方科技集团股份有限公司 Quilt kicking prevention device and using method thereof
CN110946555B (en) * 2019-12-19 2022-06-07 山东省科学院自动化研究所 Sudden stop of respiration detection alarm system
CN113257415A (en) * 2020-02-12 2021-08-13 阿里巴巴集团控股有限公司 Health data collection device and system
CN113757959B (en) * 2020-06-05 2022-09-27 广东美的制冷设备有限公司 Air conditioner, human body detection module control method thereof and readable storage medium
CN112014837B (en) * 2020-08-03 2023-06-20 杭州电子科技大学 Sign contactless intelligent monitoring system based on millimeter wave radar
TWI774224B (en) * 2021-02-03 2022-08-11 緯創資通股份有限公司 Feature enhancement and data augmentation method and motion detection device thereof
CN113384250B (en) * 2021-05-26 2022-03-15 上海交通大学 Low-power-consumption realization method of millimeter wave radar system for vital sign detection
CN113384264B (en) * 2021-06-11 2023-06-06 森思泰克河北科技有限公司 Respiratory rate detection method based on radar and sleep monitoring equipment
CN113960692B (en) * 2021-09-22 2022-10-21 北京金茂绿建科技有限公司 Sensing method and device of millimeter wave, electronic equipment and storage medium
CN116687357B (en) * 2023-08-07 2023-10-20 亿慧云智能科技（深圳）股份有限公司 Sleep monitoring method, device, equipment and storage medium based on millimeter wave radar

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140095181A1 (en) * 2012-09-28 2014-04-03 General Electric Company Methods and systems for managing performance based sleep patient care protocols
CN103006225A (en) * 2013-01-11 2013-04-03 湖南纳雷科技有限公司 Sleep monitoring instrument capable of monitoring breathing state in sleep
CN105182322B (en) * 2015-08-31 2017-12-15 西北大学 Passive type localization method based on reflected signal phase difference
CN105476602B (en) * 2015-11-25 2018-11-06 方姝阳 Contactless humanbody life sign measurement method and device
CN106419841A (en) * 2016-09-13 2017-02-22 深圳市迈迪加科技发展有限公司 Method, device and system for evaluating sleep
CN106821347B (en) * 2016-12-20 2020-05-05 中国人民解放军第三军医大学 FMCW broadband life detection radar respiration and heartbeat signal extraction algorithm

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