Vital sign and consciousness condition monitoring system based on active and passive radars

Abstract

The invention discloses a vital sign and consciousness condition monitoring system based on active and passive radars, which adopts a low-sidelobe high-gain high-sensitivity double-frequency receiving antenna to receive millimeter wave echo signals and brain wave signals on the basis of monitoring vital signs by the existing millimeter wave radar, namely Ka wave band and brain wave band signals can be received. Meanwhile, an extremely-low-frequency (brain wave band signal frequency band: 0-20MHz) high-sensitivity receiver is additionally arranged in the high-sensitivity receiver module and is used for receiving and conditioning brain wave radiation signals, and then sampling, analyzing and processing are carried out in the signal processing module; the analysis and processing data result is compared with the analysis and processing data result, stored by the data storage module, of the normal person, and when the difference is larger than a threshold value, it is indicated that the vital signs or consciousness conditions of the patient are abnormal, and an early warning signal is sent out. The non-contact monitoring system is based on active and passive radars, vital sign signals and electroencephalogram signals are accurately collected, real-time, continuous and dynamic monitoring of vital signs and consciousness conditions of a patient is achieved, and therefore rapid rehabilitation of the patient under the good rest condition is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of life sign and consciousness status monitoring, and more specifically, relates to a life sign and consciousness status monitoring system based on active and passive radars. Background Art

[0002] Monitoring the vital signs and consciousness of hospitalized patients and elderly patients with chronic diseases plays a very important role in clinical observation. Changes in the patient's vital signs and consciousness are closely related to the progression of the disease. If the patient's condition changes are not discovered in time, the rescue time will be delayed, which will have irreversible consequences and have a serious impact on the patient's prognosis.

[0003] In particular, real-time preventive monitoring of the postoperative consciousness of patients at high risk of delirium can provide early interventional treatment and reduce the impact of sequelae caused by delirium, which is of great significance. In addition, for patients with chronic geriatric diseases with rapid onset and rapid progression of the disease, it is not convenient to use professional instruments for daily health monitoring in real time. Early detection of signs of disease, rapid response and treatment strategies, and reduction of morbidity and mortality rates are also of far-reaching significance.

[0004] Therefore, the current key research direction is to achieve contactless, sustainable, and fully dynamic condition monitoring for hospitalized patients and patients with chronic geriatric diseases, ensure timely and accurate monitoring of patients' condition changes, and improve the effectiveness of patient condition monitoring.

[0005] Existing monitoring of vital signs and consciousness status mainly relies on traditional clinical observation by medical staff and instrument monitoring of key patients.

[0006] Based on traditional clinical observation, the monitoring of the patient's heart and respiratory status usually uses ECG monitoring and blood oxygen detection kits to detect the patient's heart rhythmic electrical activity and oxygen saturation according to the condition. When using, medical staff place electrodes on the patient's wrists, fingers, etc. by the ECG monitor. By recording parameters such as heart rhythmic electrical activity and oxygen saturation, the functional status of the vital signs of the monitored person is reflected.

[0007] At present, the monitoring of the patient's state of consciousness is mainly carried out by using instruments according to the condition, such as EEG monitoring, bispectral index (BIS) monitoring, etc. Electrodes are placed on the patient's scalp using an EEG device, and the rhythmic electrical activity of brain cell groups is recorded through the electrodes to reflect the state of consciousness of the monitored person.

[0008] Traditional clinical monitoring has obvious limitations and challenges:

[0009] Chronic geriatric diseases are characterized by rapid onset and rapid progression, so real-time monitoring of changes in their condition is of great significance for early warning and early treatment. However, it is not realistic to use monitoring equipment to monitor chronic geriatric patients in real time, both from the perspective of cost and convenience.

[0010] For real-time preventive monitoring of the postoperative consciousness of patients at risk of delirium, patients are divided into different nursing levels according to their condition, and their patrol frequencies vary (special nursing requires close observation; first-level nursing patrols every hour; second-level nursing patrols every two hours; third-level nursing patrols every three hours). Even with special-level nursing, it is impossible to ensure real-time dynamic evaluation and monitoring of patients at the bedside. There is a blank observation period, and it is difficult to detect changes in the condition in time. However, the real-time use of EEG monitoring equipment for preventive monitoring of patients at risk of delirium not only occupies precious medical resources, but the connection of complex electrodes on the head also increases the physical burden on patients.

[0011] In the Chinese invention patent entitled "A millimeter-wave-based non-contact vital signs monitoring method and system", which was authorized on May 14, 2024, with the authorization announcement number CN116831540B, the method transmits a millimeter-wave radar signal to the target human body, receives the echo signal reflected by the chest vibration of the target human body; the echo signal is mixed with the transmitted millimeter-wave radar signal to obtain an intermediate frequency signal, and the frequency and phase of the intermediate frequency signal are extracted; a frequency domain signal is constructed according to the frequency and phase of the intermediate frequency signal, and the respiratory signal is filtered out based on the difference in the spectral characteristics between the respiratory signal and the heartbeat signal to obtain the heartbeat signal. The invention can perform real-time and efficient non-contact measurement of key vital signs such as the respiratory and heartbeat signals of the target human body, enabling users to understand the current vital signs information such as the respiratory and heartbeat frequency of the monitored object, with small error fluctuations and high measurement accuracy.

[0012] Similarly, in the Chinese invention patent authorized on July 12, 2024, with the authorization announcement number CN114403820B and the name "A method and system for detecting vital signs of a mobile target", chirp signals with different slope frequencies are transmitted based on MIMO technology to obtain multiple groups of signal data with different distance resolutions; the target distance information is obtained and the target phase signal is extracted; based on the modal decomposition algorithm, the heartbeat signal and breathing signal of the target are decomposed from the target phase signal to estimate the target heart rate and breathing frequency. The present invention uses non-contact millimeter-wave radar detection to detect the breathing rate and heart rate of mobile targets. Compared with wearable and contact devices, it provides users with a pleasant experience while ensuring privacy; compared with other traditional non-contact vital signs monitoring methods, this method does not require the monitored person to be sitting on a chair or lying on a bed with the chest facing the radar device, and supports the target to carry out normal activities in the monitoring area to achieve vital signs monitoring.

[0013] However, existing millimeter-wave radar-based vital signs monitoring methods mainly obtain vital signs such as breathing and heartbeat signals, and are unable to monitor the state of consciousness. Summary of the invention

[0014] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a vital sign and consciousness status monitoring system based on active and passive radars, so as to accurately collect vital sign signals and electroencephalogram signals, and realize real-time, continuous and dynamic monitoring of the patient's vital signs and consciousness status.

[0015] To achieve the above-mentioned purpose, the present invention provides a vital sign and consciousness monitoring system based on active and passive radars, comprising:

[0016] A radar excitation source, used for generating a millimeter-wave radar excitation signal;

[0017] The transmitter module and the low-sidelobe high-gain transmitting antenna, the millimeter-wave radar excitation signal is amplified by the millimeter-wave transmitter in the transmitter module and then transmitted to the low-sidelobe high-gain transmitting antenna, which transmits the millimeter-wave radar signal to the monitored person;

[0018] It is characterized by further comprising:

[0019] A dual-frequency receiving antenna with low sidelobe, high gain and high sensitivity is used to receive the millimeter-wave radar signal reflected by the monitored person, i.e., the millimeter-wave echo signal, and the radiated brain wave signal and transmit them to a high-sensitivity receiver module. The millimeter-wave echo signal reflects vital signs, and the brain wave signal reflects the state of consciousness;

[0020] The high-sensitivity receiver module consists of two parts: a millimeter wave receiver and an extremely low frequency high-sensitivity receiver. The millimeter wave receiver is used to condition the millimeter wave echo signal, and the extremely low frequency high-sensitivity receiver is used to condition the brain wave signal.

[0021] The signal processing module is used to sample and analyze the conditioned millimeter wave echo signal and brain wave signal to obtain the vital and brain wave characteristic data of the monitored person;

[0022] A data storage module is used to store the vital and brain wave characteristic data obtained by the signal processing module when the monitored person is a normal person;

[0023] The alarm module is used to compare the vital and brain wave characteristic data analyzed and processed by the signal processing module with the vital and brain wave characteristic data stored by the data storage module when the monitored person is a patient. When the difference is greater than a threshold, it indicates that the patient's vital signs or consciousness state are abnormal, and a warning signal is issued.

[0024] The object of the invention of the present invention is achieved in this way:

[0025] The present invention is a vital sign and consciousness status monitoring system based on active and passive radars. On the basis of existing millimeter wave radar monitoring of vital signs, a low sidelobe, high gain, high sensitivity dual-frequency receiving antenna is used to receive millimeter wave echo signals and brain wave signals, that is, Ka band and brain wave band signals can be received. At the same time, an extremely low frequency (brain wave band signal frequency band: 0-20MHz) high sensitivity receiver is added to the high sensitivity receiver module to condition the brain wave radiation signal, and then sampling, analysis and processing are performed in the signal processing module. The data results of the analysis and processing are compared with the data results of the analysis and processing of normal people stored in the data storage module. When the difference is greater than a threshold value, it indicates that the patient's vital signs or consciousness status are abnormal, and an early warning signal is issued.

[0026] The present invention is a non-contact monitoring system based on active and passive radars, which ensures the accurate collection and high-speed processing of the patient's vital signs and EEG signals, and realizes real-time, continuous, dynamic, and widely applicable monitoring of the patient's vital signs and consciousness status, effectively breaking through the limitations of traditional disease monitoring and evaluation methods for elderly chronic disease patients and postoperative consciousness monitoring of patients with delirium risk, which lacks real-time, convenience, and wide applicability, greatly reduces the work pressure of medical staff, and provides solid technical support for early warning and interventional treatment of changes in the patient's physical condition and reduction of sequelae. At the same time, the present invention can perform uninterrupted contactless monitoring of the vital signs of hospitalized patients, which is conducive to the rapid recovery of patients under good rest conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the principle of a specific implementation of the vital sign and consciousness status monitoring system based on active and passive radars of the present invention;

[0028] Figure 2 yes Figure 1 The schematic diagram of the millimeter wave transmitter shown;

[0029] Figure 3 yes Figure 1 The schematic diagram of the millimeter wave receiver shown in FIG.

[0030] Figure 4 yes Figure 1 The schematic diagram of the principle of the extremely low frequency high sensitivity receiver is shown;

[0031] Figure 5 yes Figure 1 The structural schematic diagram of the self-calibration module shown;

[0032] Figure 6 This is a flow chart for the amplitude and phase self-calibration of the radar receiving and transmitting link;

[0033] Figure 7 It is a schematic diagram of monitoring a monitored person by the vital signs and consciousness status monitoring system based on active and passive radars of the present invention. DETAILED DESCRIPTION

[0034] The specific implementation of the present invention is described below in conjunction with the accompanying drawings so that those skilled in the art can better understand the present invention. It should be noted that in the following description, when the detailed description of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0035] Figure 1 It is a schematic diagram of the principle of a specific implementation of the vital sign and consciousness status monitoring system based on active and passive radars of the present invention.

[0036] In this embodiment, if Figure 1 As shown, the vital signs and consciousness status monitoring system based on active and passive radars of the present invention includes: a radar excitation source 1, a transmitter module 2, a low-sidelobe and high-gain transmitting antenna 3, a low-sidelobe, high-gain and high-sensitivity dual-frequency receiving antenna 4, a high-sensitivity receiver module 5, a signal processing module 6, a data storage module 7 and an alarm module 8.

[0037] The radar excitation source 1 generates a millimeter-wave radar excitation signal, which is amplified by the millimeter-wave transmitter 201 in the transmitter module 2 and then transmitted to the low-sidelobe and high-gain transmitting antenna 3 to transmit the millimeter-wave radar signal to the monitored person.

[0038] In this embodiment, the radar excitation source 1 is a signal generation module with high frequency stability, which has the ability to output signals at high frequency and wide frequency band. The radar excitation source improved based on the signal generation module with high frequency stability can achieve the design purpose of radar software and realize the detection signal transmission and reception required for monitoring with an open system structure.

[0039] The transmitter module 2 is composed of a millimeter wave (Ka band) transmitter 201, a direct circuit 202 and a first microwave switch 203. Figure 2As shown, the millimeter wave transmitter 201 is composed of an attenuator 2011, a driving amplifier 2012, a power amplifier 2013, a coupler 2014, and a detector 2015. The attenuator 2011 attenuates the millimeter wave radar excitation signal, which is then amplified by the driving amplifier 2012 and then power amplified by the power amplifier 2013. The millimeter wave radar excitation signal amplified by the power amplifier 2013 is divided into two parts by the coupler 2014, one part is transmitted to the detector 2015 to detect the output signal, and the result after detection is fed back to the attenuator 2011 for controlling the signal level, and the other part (after the self-calibration module 9) is transmitted to the low sidelobe and high gain transmitting antenna 3 to radiate to the open space, that is, to transmit the millimeter wave radar signal to the monitored person, wherein the low sidelobe and high gain transmitting antenna 3 is a Ka band antenna. Among them, the driving amplifier is used for pre-amplification of the transmission signal so that the power amplifier 2013 can further amplify the signal. The power amplifier 2013 is a high-power amplifier, which is realized by a simple bridge or Wilkison power synthesis and is used to amplify the signal power according to the design requirements. The coupler 2014 and the detector 2015 detect the signal power after being amplified by the power amplifier 2013. The attenuator 2011 constitutes an automatic level balancing circuit. When the signal power is large, the attenuation ratio is increased, and vice versa, the attenuation ratio is reduced.

[0040] The low sidelobe, high gain, and high sensitivity dual-frequency receiving antenna 4 receives the millimeter wave radar signal reflected by the monitored person, i.e., the millimeter wave echo signal, and the radiated brain wave signal and transmits them to the high sensitivity receiver module 5, wherein the millimeter wave echo signal reflects vital signs and the brain wave signal reflects the state of consciousness. The low sidelobe, high gain, and high sensitivity dual-frequency receiving antenna 4 is a co-aperture microstrip antenna covering the extremely low frequency (0-20MHz) and Ka band.

[0041] The high-sensitivity receiver module 5 consists of two parts: a millimeter wave receiver 501 and an extremely low frequency high-sensitivity receiver 502. The millimeter wave receiver 501 is used to condition the millimeter wave echo signal, and the extremely low frequency high-sensitivity receiver 502 is used to condition the brain wave signal.

[0042] The millimeter wave receiver 501 covers the Ka band. It includes a limiter 5011, a low noise amplifier 5012, a down converter 5013, a filter 5014 and a demodulator 5015. The reflected millimeter wave radar signal, i.e., the millimeter wave echo signal, is received by the dual-frequency receiving antenna 4 with low side lobe, high gain and high sensitivity and then transmitted to the limiter 5011. The limiter 5011 limits the high power signal exceeding the threshold, amplifies it by the low noise amplifier 5012, performs down-conversion processing by the down converter 5013, filters out the out-of-band signal by the filter 5014, and then demodulates it by the demodulator 5015 to obtain the conditioned millimeter wave echo signal. The conditioned millimeter wave echo signal is an IQ signal.

[0043] The extremely low frequency high sensitivity receiver 502 covers the extremely low frequency band, i.e., the brain wave band, and includes a limiter 5021, a low noise amplifier 5022, a filter 5023, and a demodulator 5024. The radiated brain wave signal is received by the low side lobe, high gain, and high sensitivity dual frequency receiving antenna 4 and then transmitted to the limiter 5021. The limiter 5021 limits the high power signal exceeding the threshold, amplifies it by the low noise amplifier 5022, filters out the out-of-band signal by the filter 5023, and then demodulates the conditioned brain wave signal by the demodulator 5024. The conditioned brain wave signal is an IQ signal.

[0044] The signal processing module 6 samples the conditioned millimeter wave echo signal and the brain wave signal and performs analysis and processing to obtain the vital and brain wave characteristic data of the monitored person. In the specific implementation process, the millimeter wave echo signal can also be processed to obtain the breathing and heartbeat signals and the corresponding frequencies.

[0045] The data storage module 7 is used to store the vital and brain wave characteristic data obtained by the signal processing module when the monitored person is a normal person, and can also store the signal characteristics of the vital signs and consciousness of abnormal patients for evaluation and analysis of later scientific research. The alarm module 8 is used to compare the vital and brain wave characteristic data analyzed and processed by the signal processing module with the vital and brain wave characteristic data stored by the data storage module when the monitored person is a patient. When the difference is greater than the threshold, it indicates that the patient's vital signs or consciousness are abnormal, and an early warning signal is issued.

[0046] In this embodiment, the signal processing module 6 is designed with a PXIe bus structure, which can sample the intermediate frequency echo signal, control the interface of the radar front end, and analyze and process the echo characteristics.

[0047] The errors caused by active devices such as low-noise amplifiers in millimeter-wave receivers and extremely low-frequency high-sensitivity receivers are important factors affecting monitoring accuracy. In addition, the errors caused by them are inconsistent under different working conditions. The impact of the errors on the monitoring results cannot be deducted by calibrating the errors in advance. Therefore, in order to obtain more accurate monitoring results, the receiving link errors need to be accurately calibrated.

[0048] like Figure 1 As shown, the active and passive radar-based vital sign and consciousness status monitoring system of the present invention also includes a self-calibration module 9. Figure 5 As shown, the self-calibration module 9 is composed of a coupler 901, a second microwave switch 902, a first matching impedance 903, a third microwave switch 904, a second matching impedance 905, and a fourth microwave switch 906. The input of the coupler 901 comes from the transmitter module 2, and the output is two-way, one way to the connection end 1 of the second microwave switch 902, and the other way to the connection end 1 of the third microwave switch 904. The connection ends 2 and 3 of the second microwave switch 902 are respectively connected to the first matching impedance 903 and the transmitting antenna 3 with low side lobe and high gain. The second microwave switch 902 selects the connection end 1 to be connected to the connection end 2 or the connection end 3. The connection ends 2 and 3 of the third microwave switch 904 are connected to the second matching impedance 905 and the high-sensitivity receiver module 5 respectively. The third microwave switch 904 selects the connection end 1 to be connected to the connection end 2 or the connection end 3. The connection ends 1 and 2 of the fourth microwave switch 906 are connected to the low-sidelobe, high-gain, and high-sensitivity dual-frequency receiving antenna 4 and the high-sensitivity receiver module 5 respectively. When it is closed, the low-sidelobe, high-gain, and high-sensitivity dual-frequency receiving antenna 4 and the high-sensitivity receiver module 5 are connected. When it is disconnected, the low-sidelobe, high-gain, and high-sensitivity dual-frequency receiving antenna 4 and the high-sensitivity receiver module 5 are disconnected.

[0049] The transmitter module 2 also includes a through circuit 202 and a first microwave switch 203. The connection terminal 1 of the first microwave switch 203 is connected to the millimeter-wave radar excitation signal generated by the radar excitation source 1, and then one of the connection terminals 2, 3, and 4 is selected for connection, wherein the connection terminal 2 is connected to the through circuit 202, the connection terminal 3 is connected to the millimeter-wave transmitter 201, and the connection terminal 4 is empty.

[0050] In this embodiment, the radar excitation source 1 covers the extremely low frequency 0-20 MHz and millimeter wave bands. During calibration, an excitation signal is used to send an extremely low frequency signal to calibrate the link, but it is not necessary during testing.

[0051] First, if Figure 6 As shown, the radar receiving chain is calibrated for amplitude and phase:

[0052] Step S101: Select the connection terminal 4 of the first microwave switch 203 to connect or disconnect the radar excitation source 1. The millimeter wave radar excitation signal S1(ω) generated by the radar excitation source 1 is:

[0053]

[0054] Among them, |S1(ω)| is the amplitude of the millimeter wave radar excitation signal, is the phase of the millimeter-wave radar excitation signal, ω is the angular frequency of the millimeter-wave radar excitation signal;

[0055] Step S102: Select the connection end 2 of the first microwave switch 203 to connect, the millimeter wave radar excitation signal S1 (ω) is input to the coupler 901 of the self-calibration module 9 through the first microwave switch 203 and the direct circuit 202 in the transmitter module 2, select the connection end 2 of the second microwave switch 902 to connect, that is, the coupler 901 is connected to the first matching impedance 903, and at the same time, select the connection end 3 of the third microwave switch 904 to connect, that is, the coupler 901 is connected to the high-sensitivity receiver module 5, and the fourth microwave switch 906 is disconnected. In this way, the millimeter wave radar excitation signal S1 (ω) is input to the millimeter wave receiver 501 in the high-sensitivity receiver module 5 through the first microwave switch 203 in the transmitter module 2, the direct circuit 202, the coupler 901 in the self-calibration module 9, and the third microwave switch 904 for conditioning. The conditioned millimeter wave radar signal is S2 (ω):

[0056]

[0057] Among them, |S2(ω)| is the amplitude of the conditioned millimeter-wave radar signal, is the phase of the conditioned millimeter-wave radar signal;

[0058] Step S103: Calculate the amplitude change and phase offset of the conditioned millimeter-wave radar signal S2(ω) relative to the millimeter-wave radar excitation signal S1(ω), that is, calibrate the total error L of the millimeter-wave receiver through the self-calibration module 9 of the direct circuit 202. S1 :

[0059]

[0060] in, is the total error L S1 The amplitude, is the total error L S1 The phase of

[0061] Step S104: Using the error parameter L of the third microwave switch 904 in the self-calibration module 9 K1 :

[0062]

[0063] Among them, |L K1 (ω)| is the error parameter L K1 The amplitude, is the error parameter L K1 The phase of

[0064] The error parameter L of the fourth microwave switch 906 K2 :

[0065]

[0066] Among them, |L K2 (ω)| is the error parameter L K2 The amplitude, is the error parameter L K2 The phase of

[0067] The error parameter L of the direct circuit 202 T1 :

[0068]

[0069] Among them, |L T1 (ω)| is the error parameter L T1 The amplitude, is the error parameter L T1 The phase of

[0070] Combined total error L S1 Perform vector calculation correction to obtain the radar receiving link error L during active detection S2 :

[0071]

[0072] Similarly, the millimeter wave radar excitation signal S1(ω) generated by the radar excitation source 1 in step S101 is converted into an extremely low frequency signal of 0-20 MHz, and is input into the extremely low frequency high sensitivity receiver 502 in the high sensitivity receiver module 5 in step S102 for conditioning to obtain the radar receiving link error during passive detection, which is recorded as L S ′2.

[0073] Then, when the active detection mode is performed, the radar excitation source 1 is adjusted to the Ka band to generate a millimeter-wave radar excitation signal. At the same time, for the first microwave switch 203, the connection end 3 is selected to be connected, and the millimeter-wave radar excitation signal is input into the millimeter-wave transmitter 201. For the second microwave switch 902 in the self-calibration module 9, the connection end 3 is selected to be connected, so that the millimeter-wave radar excitation signal is amplified by the millimeter-wave transmitter 201 in the transmitter module 2 and then transmitted to the transmitting antenna 3 with low side lobe and high gain, so as to transmit the millimeter-wave radar signal to the monitored person. For the third microwave switch 904 in the self-calibration module 9, the connection end 2 is selected to be connected, that is, the second matching impedance 905 is connected to play the role of impedance matching. For the fourth microwave switch 906 in the self-calibration module 9, it is closed, so that the dual-frequency receiving antenna 4 with low side lobe, high gain and high sensitivity receives the millimeter-wave radar signal reflected by the monitored person, that is, the millimeter-wave echo signal and transmits it to the high-sensitivity receiver module 5, and is conditioned by the millimeter-wave receiver 501 to obtain the conditioned millimeter-wave echo signal T1;

[0074] After sampling in the signal processing module 6, the millimeter wave echo signal T1 is calibrated in amplitude and phase before analysis and processing to obtain the millimeter wave echo signal T before the radar enters the receiving link. R1 :

[0075]

[0076] For millimeter wave echo signal T R1 Perform analysis and processing to obtain the vital characteristics data of the monitored person;

[0077] When the passive detection mode is performed, the radar excitation source 1 is turned off or the connection end 4 of the first microwave switch 203 is selected for connection, the connection end 2 of the second microwave switch 902 is selected for connection, that is, the coupler 901 is connected to the first matching impedance 903, the connection end 2 of the third microwave switch 904 is selected for connection, that is, the coupler 901 is connected to the second matching impedance 905, and the fourth microwave switch 906 is closed, so that the low sidelobe, high gain and high sensitivity dual-frequency receiving antenna 4 receives the brain wave signal radiated by the monitored person and transmits it to the high sensitivity receiver module 5, and the conditioned brain wave signal T1′ is obtained after conditioning by the extremely low frequency and high sensitivity receiver 502;

[0078] After sampling in the signal processing module 6, the amplitude and phase of the brain wave signal T1′ are calibrated before analysis and processing to obtain the brain wave signal T before the radar enters the receiving link. R ′1:

[0079]

[0080] For brain wave signal T R ′1 is analyzed and processed to obtain the brain wave characteristic data of the monitored person.

[0081] In this embodiment, a signal generating module having high frequency stability relative to the frequency changes of millimeter wave echo signals and brain wave radiation signals is used as the radar excitation source 1, and the frequencies of the conditioned millimeter wave echo signals and brain wave signals can be calibrated.

[0082] The steps of self-calibration of the millimeter wave receiver 501 frequency are as follows:

[0083] For the first microwave switch 203, the connection end 3 is selected for connection, and the connection end 2 of the second microwave switch 902 is selected for connection, that is, the coupler 901 is connected to the first matching impedance 903. At the same time, the connection end 3 of the third microwave switch 904 is selected for connection, that is, the coupler 901 is connected to the high-sensitivity receiver module 5, and the fourth microwave switch 906 is disconnected. The radar excitation source 1 generates a millimeter-wave radar excitation signal with a frequency of ω0, and passes through the first microwave switch 203 in the transmitter module 2, the millimeter-wave transmitter 201, the self-calibration module 9, and the millimeter-wave receiver 501 in the high-sensitivity receiver module 5 to obtain a conditioned millimeter-wave radar signal with a frequency of ω1. The frequency offset of the millimeter-wave receiver 501 obtained by using the above two frequencies ω1 and ω0 is Δω:

[0084] Δω=ω1-ω0

[0085] Using the frequency offset Δω, the frequency of the millimeter wave echo signal T1 is calibrated in the active detection mode, and the frequency of the calibrated millimeter wave echo signal is:

[0086] ω R1 =ω T1 -Δω

[0087] Among them, ω T1 is the frequency of the millimeter wave echo signal T1 measured by the radar millimeter wave receiver, ω R1 is the frequency of the calibrated millimeter wave echo signal, that is, the millimeter wave echo signal T before the radar enters the receiving link R1 frequency.

[0088] The frequency self-calibration steps of the low-frequency high-sensitivity receiver 502 are as follows:

[0089] For the first microwave switch 203, the connection end 2 is selected for connection, the connection end 2 of the second microwave switch 902 is selected for connection, that is, the coupler 901 is connected to the first matching impedance 903, and at the same time, the connection end 3 of the third microwave switch 904 is selected for connection, that is, the coupler 901 is connected to the high-sensitivity receiver module 5, and the fourth microwave switch 906 is disconnected. The radar excitation source 1 generates an extremely low frequency signal with a frequency of ω0′, which passes through the first microwave switch 203 in the transmitter module 2, the direct circuit 202, the self-calibration module 9, and the extremely low frequency high-sensitivity receiver 502 in the high-sensitivity receiver module 5 to obtain a conditioned extremely low frequency signal with a frequency of ω1′. The frequency offset of the low-frequency high-sensitivity receiver 502 is obtained by using the above two frequencies ω′1 and ω′0:

[0090] Δω′=ω′1-ω′0

[0091] Using the frequency offset Δω′, the brain wave signal T1′ is frequency calibrated in the passive detection mode, and the calibrated brain wave signal frequency is obtained as follows:

[0092] ω′ R1 =ω′ T1 -Δω′

[0093] Among them, ω′ T1 is the frequency of the brain wave signal T1′ measured by the radar extremely low frequency high-sensitivity receiver, ω′ R1 is the brain wave signal frequency after calibration, that is, the brain wave signal T′ before the radar enters the receiving link R1 frequency.

[0094] In this embodiment, the present invention further includes a timing control module 10, which uses a PLL inside the FPGA to generate a clock signal of a frequency required for coherent signal processing, to ensure that the timing of each hardware control signal strictly meets the timing design requirements.

[0095] Figure 7 It is a schematic diagram of monitoring a monitored person by the vital signs and consciousness status monitoring system based on active and passive radars of the present invention.

[0096] In this embodiment, if Figure 7 As shown, the vital signs and consciousness status monitoring system based on active and passive radars of the present invention utilizes active and passive detection to perform uninterrupted and contactless continuous monitoring of the vital signs and consciousness status of the monitored person, thereby facilitating the rapid recovery of the monitored person (patient) under good rest conditions.

[0097] Although the above describes the illustrative specific embodiments of the present invention to facilitate those skilled in the art to understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A vital sign and consciousness status monitoring system based on active and passive radar, comprising: A radar excitation source, used for generating a millimeter-wave radar excitation signal; The transmitter module and the low-sidelobe high-gain transmitting antenna, the millimeter-wave radar excitation signal is amplified by the millimeter-wave transmitter in the transmitter module and then transmitted to the low-sidelobe high-gain transmitting antenna, which transmits the millimeter-wave radar signal to the monitored person; It is characterized by further comprising: A dual-frequency receiving antenna with low sidelobe, high gain and high sensitivity is used to receive the millimeter-wave radar signal reflected by the monitored person, i.e., the millimeter-wave echo signal, and the radiated brain wave signal and transmit them to a high-sensitivity receiver module. The millimeter-wave echo signal reflects vital signs, and the brain wave radiation signal reflects the state of consciousness; The high-sensitivity receiver module consists of two parts: a millimeter wave receiver and an extremely low frequency high-sensitivity receiver. The millimeter wave receiver is used to condition the millimeter wave echo signal, and the extremely low frequency high-sensitivity receiver is used to condition the brain wave radiation signal. The signal processing module is used to sample and analyze the conditioned millimeter wave echo signal and brain wave radiation signal to obtain the vital and brain wave characteristic data of the monitored person; A data storage module is used to store the vital and brain wave characteristic data obtained by the signal processing module when the monitored person is a normal person; The alarm module is used to compare the vital and brain wave characteristic data analyzed and processed by the signal processing module with the vital and brain wave characteristic data stored by the data storage module when the monitored person is a patient. When the difference is greater than a threshold, it indicates that the patient's vital signs or consciousness state are abnormal, and a warning signal is issued.

2. The vital signs and consciousness status monitoring system based on active and passive radar according to claim 1 is characterized in that: It also includes a self-calibration module, which is composed of a coupler, a second microwave switch, a first matching impedance, a third microwave switch, a second matching impedance, and a fourth microwave switch; The input of the coupler comes from the transmitter module, and the output is two-way, one way to the connection terminal 1 of the second microwave switch, and the other way to the connection terminal 1 of the third microwave switch. The connection terminals 2 and 3 of the second microwave switch are respectively connected to the first matching impedance, low sidelobe and high gain transmitting antenna. The second microwave switch selects the connection terminal 1 to be connected to the connection terminal 2 or the connection terminal 3. The connection terminals 2 and 3 of the third microwave switch are respectively connected to the second matching impedance and high sensitivity receiver module. The third microwave switch selects the connection terminal 1 to be connected to the connection terminal 2 or the connection terminal 3. The connection terminals 1 and 2 of the fourth microwave switch are respectively connected to the low sidelobe, high gain and high sensitivity dual-frequency receiving antenna and the high sensitivity receiver module. When it is closed, the low sidelobe, high gain and high sensitivity dual-frequency receiving antenna is connected to the high sensitivity receiver module. When it is disconnected, the low sidelobe, high gain and high sensitivity dual-frequency receiving antenna is disconnected from the high sensitivity receiver module. The transmitter module also includes a through circuit and a first microwave switch, wherein a connection terminal 1 of the first microwave switch is connected to a millimeter-wave radar excitation signal generated by a radar excitation source, and then one of connection terminals 2, 3, and 4 is selected for connection, wherein connection terminal 2 is connected to the through circuit, connection terminal 3 is connected to the millimeter-wave transmitter, and connection terminal 4 is empty.

3. The vital signs and consciousness status monitoring system based on active and passive radar according to claim 1 is characterized in that: First, the radar receiving chain is self-calibrated in amplitude and phase: Step S101: Select the connection terminal 4 of the first microwave switch to connect or disconnect the radar excitation source. The millimeter-wave radar excitation signal S1(ω) generated by the radar excitation source is: Among them, |S1(ω)| is the amplitude of the millimeter wave radar excitation signal, is the phase of the millimeter-wave radar excitation signal, (ω) is the angular frequency of the millimeter-wave radar excitation signal; Step S102: Select the connection end 2 of the first microwave switch to connect, the millimeter wave radar excitation signal S1 (ω) is input to the coupler of the self-calibration module through the first microwave switch and the direct circuit in the transmitter module, select the connection end 2 of the second microwave switch to connect, that is, the coupler is connected to the first matching impedance, and at the same time, select the connection end 3 of the third microwave switch to connect, that is, the coupler is connected to the high-sensitivity receiver module, and the fourth microwave switch is disconnected. In this way, the millimeter wave radar excitation signal S1 (ω) is input to the millimeter wave receiver in the high-sensitivity receiver module through the first microwave switch in the transmitter module, the direct circuit, the coupler in the self-calibration module, and the third microwave switch for conditioning. The conditioned millimeter wave radar signal is S2 (ω): Among them, |S2(ω)| is the amplitude of the conditioned millimeter-wave radar signal, is the phase of the conditioned millimeter-wave radar signal; Step S103: Calculate the amplitude change and phase offset of the conditioned millimeter-wave radar signal S2(ω) relative to the millimeter-wave radar excitation signal S1(ω), that is, calibrate the total error L of the transmitter module, the self-calibration module, and the high-sensitivity receiver module. S1 : in, is the total error L S1 The amplitude, is the total error L S1 The phase of Step S104: Using the error parameter L of the third microwave switch in the self-calibration module K1 : Among them, |L K1 (ω)| is the error parameter L K1 The amplitude, is the error parameter L K1 The phase of Error parameter L of the fourth microwave switch K2 : Among them, |L K2 (ω)| is the error parameter L K2 The amplitude, is the error parameter L K2 The phase of Error parameter L of the direct circuit T1 : Among them, |L T1 (ω)| is the error parameter L T1 The amplitude, is the error parameter L T1 The phase of Combined total error L S1 Perform vector calculation correction to obtain the radar receiving link error L during active detection S2 : Similarly, the millimeter wave radar excitation signal S1(ω) generated by the radar excitation source in step S101 is converted into an extremely low frequency signal of 0-20 MHz, and is input into the extremely low frequency high sensitivity receiver in the high sensitivity receiver module in step S102 for conditioning to obtain the radar receiving link error during passive detection, which is recorded as L′ S2 ; Then, when the active detection mode is performed, the radar excitation source is adjusted to the Ka band to generate a millimeter-wave radar excitation signal. At the same time, for the first microwave switch, the connection end 3 is selected to connect, and the millimeter-wave radar excitation signal is input into the millimeter-wave transmitter. For the second microwave switch in the self-calibration module, the connection end 3 is selected to connect, so that the millimeter-wave radar excitation signal is amplified by the millimeter-wave transmitter in the transmitter module and transmitted to the transmitting antenna with low side lobe and high gain, so as to transmit the millimeter-wave radar signal to the monitored person. For the third microwave switch in the self-calibration module, the connection end 2 is selected to connect, that is, to connect the second matching impedance, so as to play the role of impedance matching. For the fourth microwave switch in the self-calibration module, it is closed, so that the dual-frequency receiving antenna with low side lobe, high gain and high sensitivity receives the millimeter-wave radar signal reflected by the monitored person, that is, the millimeter-wave echo signal and transmits it to the high-sensitivity receiver module, and is conditioned by the millimeter-wave receiver to obtain the conditioned millimeter-wave echo signal T1; After sampling in the signal processing module, the millimeter wave echo signal T1 is calibrated in amplitude and phase before analysis and processing to obtain the millimeter wave echo signal T before the radar enters the receiving link. R1 : For millimeter wave echo signal T R1 Perform analysis and processing to obtain the vital characteristics data of the monitored person; When the passive detection mode is performed, the radar excitation source is turned off or the connection end 4 of the first microwave switch is selected for connection, the connection end 2 of the second microwave switch is selected for connection, that is, the coupler is connected to the first matching impedance, the connection end 2 of the third microwave switch is selected for connection, that is, the coupler is connected to the second matching impedance, and the fourth microwave switch is closed, so that the low sidelobe, high gain and high sensitivity dual-frequency receiving antenna receives the brain wave signal radiated by the monitored person and transmits it to the high sensitivity receiver module, and the conditioned brain wave signal T1′ is obtained after conditioning by the extremely low frequency and high sensitivity receiver; After sampling in the signal processing module, the amplitude and phase of the brain wave signal T1′ are calibrated before analysis and processing to obtain the brain wave signal T′ before the radar enters the receiving link. R1 : For brain wave signal T′ R1 Analyze and process to obtain the brain wave characteristic data of the monitored person.

4. The vital signs and consciousness status monitoring system based on active and passive radar according to claim 3 is characterized in that: Self-calibration of mmWave receiver frequency: For the first microwave switch, select the connection end 3 to connect, select the connection end 2 of the second microwave switch to connect, that is, the coupler is connected to the first matching impedance, and at the same time, select the connection end 3 of the third microwave switch to connect, that is, the coupler is connected to the high-sensitivity receiver module, and the fourth microwave switch is disconnected. The radar excitation source generates a millimeter-wave radar excitation signal with a frequency of ω0, and passes through the first microwave switch in the transmitter module, the millimeter-wave transmitter, the self-calibration module, and the millimeter-wave receiver in the high-sensitivity receiver module to obtain a conditioned millimeter-wave radar signal with a frequency of ω1. The frequency offset of the millimeter-wave receiver obtained by using the above two frequencies ω1 and ω0 is Δω: Δω=ω1-ω0 Using the frequency offset Δω, the frequency of the millimeter wave echo signal T1 is calibrated in the active detection mode, and the frequency of the calibrated millimeter wave echo signal is: oh R1 =ω T1 -See Among them, ω T1 is the frequency of the millimeter wave echo signal T1 measured by the radar millimeter wave receiver, ω R1 is the frequency of the calibrated millimeter wave echo signal, that is, the millimeter wave echo signal T before the radar enters the receiving link R1 frequency; Self-calibration of low frequency high sensitivity receiver frequency: For the first microwave switch, select the connection end 2 to connect, select the connection end 2 of the second microwave switch to connect, that is, the coupler is connected to the first matching impedance, and at the same time, select the connection end 3 of the third microwave switch to connect, that is, the coupler is connected to the high-sensitivity receiver module, and the fourth microwave switch is disconnected. The radar excitation source generates an extremely low frequency signal with a frequency of ω′0, and passes through the first microwave switch in the transmitter module, the direct circuit, the self-calibration module, and the extremely low frequency high-sensitivity receiver in the high-sensitivity receiver module to obtain a conditioned extremely low frequency signal with a frequency of ω′1. The frequency offset of the low-frequency high-sensitivity receiver is obtained by using the above two frequencies ω′1 and ω′0: Δω′=ω′1-ω′0 Using the frequency offset Δω′, the brain wave signal T1′ is frequency calibrated in the passive detection mode, and the calibrated brain wave signal frequency is obtained as follows: oh' R1 =ω′ T1 -See? Among them, ω′ T1 is the frequency of the brain wave signal T1′ measured by the radar extremely low frequency high-sensitivity receiver, ω′ R1 is the brain wave signal frequency after calibration, that is, the brain wave signal T′ before the radar enters the receiving link R1 frequency.

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