A sleep monitoring device based on millimeter-wave radar

Abstract

The present invention relates to the technical field of sleep monitoring, and particularly to a sleep monitoring device based on a millimeter-wave radar, comprising: a signal acquisition module for receiving the sleep monitoring signal transmitted and reflected back by the millimeter-wave radar; a signal processing module connected to the signal acquisition module, including a preprocessing unit for preprocessing the sleep monitoring signal to output an optimized signal; an analysis module connected to the signal processing module for analyzing the sleep monitoring signal and the physiological signal characteristics to output a sleep state analysis result; a storage module for storing the sleep monitoring signal, the optimized signal, the physiological signal characteristics, and the sleep state analysis result respectively; and a control module for determining the center frequency of the millimeter-wave radar according to the change in the signal-to-noise ratio of the sleep monitoring signal. The present invention improves the monitoring stability of the sleep monitoring device.

Description

Technical Field

[0001] The present invention relates to the technical field of sleep monitoring, and in particular to a sleep monitoring device based on millimeter-wave radar. Background Art

[0002] In the prior art, with the continuous improvement of people's attention to health, sleep quality monitoring has become a highly regarded field. There are various traditional sleep monitoring methods, but they all have certain limitations. Polysomnography (PSG) technology has long been regarded as the "gold standard" for sleep monitoring. It synchronously records various physiological signals such as electroencephalogram (EEG), electrocardiogram (ECG), electrooculogram (EOG), and electromyogram (EMG) by connecting multiple electrodes to the human body, and then comprehensively and accurately analyzes sleep staging, respiratory events, cardiovascular status, etc. However, the disadvantages of PSG technology are also very obvious. On the one hand, its equipment is complex and expensive, and requires professional technical personnel for operation and debugging, which not only keeps the detection cost high, but also limits the popularization and application of this technology in families and general medical institutions; on the other hand, numerous electrodes attached to the human body bring great discomfort to the subjects, seriously affecting the natural state of sleep, resulting in the monitoring results may not truly reflect the daily sleep situation.

[0003] Chinese Patent Publication No.: CN119112101A discloses a sleep sign monitoring method based on millimeter-wave radar, which specifically includes the following steps: Step 1-1, data acquisition; first, preset the acquisition parameters of the millimeter-wave radar. The millimeter-wave radar emits signals according to the preset parameters, the receiving antenna captures the reflected signals, and the radio frequency front-end of the millimeter-wave radar amplifies, mixes, and filters the received signals, and obtains intermediate-frequency digital signals after sampling, and sends the sampling results to the backend computing device; Step 1-2, feature extraction; extract features related to sleep posture and respiratory rate from the acquired intermediate-frequency digital signals, that is, point cloud feature generation and respiratory feature extraction; Step 1-3, sleep posture recognition; use the point cloud features and respiratory features obtained after feature extraction to recognize the user's sleep posture; Step 1-4, respiratory frequency estimation; extract effective reflection points from the point cloud data according to specific parameters for different sleep postures, and use these reflection points to accurately estimate the respiratory frequency by means of a weighted average method based on an exponential function. It can be seen that the sleep sign monitoring method based on millimeter-wave radar has the problem that the monitoring stability of the sleep monitoring device decreases due to the appearance of harmonics under electromagnetic interference in the working environment of the millimeter-wave radar, making the radar signal unstable. Summary of the Invention

[0004] To this end, the present invention provides a sleep monitoring device based on a millimeter-wave radar, which is used to overcome the problem in the prior art that due to the appearance of harmonics caused by electromagnetic interference in the environment where the millimeter-wave radar operates, the radar signal is unstable, resulting in a decrease in the monitoring stability of the sleep monitoring device.

[0005] To achieve the above object, the present invention provides a sleep monitoring device based on a millimeter-wave radar, including: a signal acquisition module, which is used to receive the sleep monitoring signal transmitted and reflected back by the millimeter-wave radar; a signal processing module, which is connected to the signal acquisition module and includes a preprocessing unit for preprocessing the sleep monitoring signal to output an optimized signal and a feature extraction unit connected to the preprocessing unit for extracting the features of the optimized signal to output physiological signal features. Among them, the preprocessing unit includes a filter for filtering the sleep monitoring signal; an analysis module, which is connected to the signal processing module and is used to analyze the sleep monitoring signal and the physiological signal features to output a sleep state analysis result; a storage module, which is respectively connected to the signal acquisition module, the signal processing module, and the analysis module and is used to store the sleep monitoring signal, the optimized signal, the physiological signal features, and the sleep state analysis result respectively; a control module, which is respectively connected to the signal acquisition module, the signal processing module, the analysis module, and the storage module and is used to determine the center frequency of the millimeter-wave radar according to the change amount of the signal-to-noise ratio of the sleep monitoring signal, or determine the cut-off frequency of the filter according to the fluctuation amplitude of the sleep monitoring signal, and determine the clock frequency of the millimeter-wave radar according to the working frequency offset amount of the millimeter-wave radar per unit time.

[0006] Further, the control module is used to determine whether the monitoring stability of the sleep monitoring device meets the requirements according to the change amount of the signal-to-noise ratio of the sleep monitoring signal. If the change amount of the signal-to-noise ratio of the sleep monitoring signal is greater than a preset first change amount, it is determined that the monitoring stability of the sleep monitoring device does not meet the requirements.

[0007] Further, when the change amount of the signal-to-noise ratio of the sleep monitoring signal is greater than the preset first change amount and less than or equal to a preset second change amount, the control module is used to preliminarily determine that the accuracy of sleep monitoring does not meet the requirements and determine whether the accuracy of sleep monitoring meets the requirements according to the fluctuation amplitude of the sleep monitoring signal.

[0008] Further, when the change amount of the signal-to-noise ratio of the sleep monitoring signal is greater than the preset second change amount, the control module is used to increase the center frequency of the millimeter-wave radar;

[0009] Among them, the increase amplitude of the center frequency of the millimeter-wave radar is determined by the difference between the change amount of the signal-to-noise ratio of the sleep monitoring signal and the preset second change amount.

[0010] Further, the control module is configured to determine whether the accuracy of sleep monitoring meets the requirements according to the fluctuation amplitude of the sleep monitoring signal. If the fluctuation amplitude of the sleep monitoring signal is greater than a preset first fluctuation amplitude, it is determined that the accuracy of sleep monitoring does not meet the requirements.

[0011] Further, when the fluctuation amplitude of the sleep monitoring signal is greater than a preset second fluctuation amplitude, the control module preliminarily determines that the working performance of the millimeter-wave radar does not meet the requirements, and determines whether the working performance of the millimeter-wave radar meets the requirements according to the working frequency offset of the millimeter-wave radar per unit time.

[0012] Further, when the fluctuation amplitude of the sleep monitoring signal is greater than the preset first fluctuation amplitude and less than or equal to the preset second fluctuation amplitude, the control module reduces the cut-off frequency of the filter.

[0013] Further, the reduction amplitude of the cut-off frequency of the filter is determined by the difference between the fluctuation amplitude of the sleep monitoring signal and the preset first fluctuation amplitude.

[0014] Further, the control module is configured to determine whether the working performance of the millimeter-wave radar meets the requirements according to the working frequency offset of the millimeter-wave radar per unit time. If the working frequency offset of the millimeter-wave radar per unit time is greater than a preset offset, it is determined that the working performance of the millimeter-wave radar does not meet the requirements, and the clock frequency of the millimeter-wave radar is reduced.

[0015] Further, the reduction amplitude of the clock frequency of the millimeter-wave radar is determined by the difference between the working frequency offset of the millimeter-wave radar per unit time and the preset offset.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows. The device of the present invention determines the center frequency of the millimeter-wave radar according to the change in the signal-to-noise ratio of the sleep monitoring signal. Since in the environment where the millimeter-wave radar operates, it may be interfered by WiFi signals, resulting in harmonics, thus making the radar signal unstable. By increasing the center frequency of the millimeter-wave radar, the interference signals received by the millimeter-wave radar can be reduced, thereby improving the signal stability. The cut-off frequency of the filter is determined according to the fluctuation amplitude of the sleep monitoring signal. Since the body micro-motion signal becomes complex due to the change in the sleep posture of the human body during signal acquisition, resulting in inaccurate extraction of features during feature extraction. By reducing the cut-off frequency of the filter, it can be ensured that while filtering noise, the useful low-frequency signal components will not be filtered out, so that the features of the body micro-motion signal with a lower frequency due to posture change can be accurately extracted. The clock frequency of the millimeter-wave radar is determined according to the operating frequency offset of the millimeter-wave radar per unit time. Since the internal components of the millimeter-wave radar age after long-term operation, resulting in a decline in the performance of the internal oscillator, thus causing the operating frequency of the millimeter-wave radar to shift. By reducing the clock frequency of the millimeter-wave radar, the signal processing can be rematched with the reduced operating frequency, ensuring the accuracy of signal processing and improving the monitoring stability of the sleep monitoring device.

[0017] Further, the device of the present invention determines the center frequency of the millimeter-wave radar by setting a preset first change amount and a preset second change amount. Since in the environment where the millimeter-wave radar operates, it may be interfered by WiFi signals, resulting in harmonics, thus making the radar signal unstable. By increasing the center frequency of the millimeter-wave radar, the interference signals received by the millimeter-wave radar can be reduced, thereby improving the signal stability and further improving the monitoring stability of the sleep monitoring device.

[0018] Further, the device of the present invention determines the cut-off frequency of the filter by setting a preset first fluctuation amplitude and a preset second fluctuation amplitude. Since the body micro-motion signal becomes complex due to the change in the sleep posture of the human body during signal acquisition, resulting in inaccurate extraction of features during feature extraction. By reducing the cut-off frequency of the filter, it can be ensured that while filtering noise, the useful low-frequency signal components will not be filtered out, so that the features of the body micro-motion signal with a lower frequency due to posture change can be accurately extracted, and the monitoring stability of the sleep monitoring device is further improved.

[0019] Furthermore, the device of the present invention determines the clock frequency of the millimeter-wave radar by setting a preset offset. Since the internal components of the millimeter-wave radar age after long-term operation, the performance of the internal oscillator deteriorates, resulting in an offset of the operating frequency of the millimeter-wave radar. By reducing the clock frequency of the millimeter-wave radar, the signal processing can be re-matched with the reduced operating frequency, ensuring the accuracy of signal processing and further improving the monitoring stability of the sleep monitoring device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the overall structural block diagram of the sleep monitoring device based on a millimeter-wave radar according to an embodiment of the present invention;

[0021] Figure 2 is the logic flow chart of the sleep monitoring device based on a millimeter-wave radar according to an embodiment of the present invention;

[0022] Figure 3 is the specific structural block diagram of the signal processing module of the sleep monitoring device based on a millimeter-wave radar according to an embodiment of the present invention;

[0023] Figure 4 is the connection structural block diagram of the signal processing module and the control module of the sleep monitoring device based on a millimeter-wave radar according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0026] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0027] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "linkage" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0028] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 as shown, which are respectively the overall structural block diagram, the logic flow chart, the specific structural block diagram of the signal processing module, and the connection structural block diagram of the connection between the signal processing module and the control module of the sleep monitoring device based on millimeter-wave radar in the embodiment of the present invention. A sleep monitoring device based on millimeter-wave radar of the present invention includes:

[0029] A signal acquisition module for receiving the sleep monitoring signal transmitted and reflected back by the millimeter-wave radar;

[0030] A signal processing module, which is connected to the signal acquisition module, includes a preprocessing unit for preprocessing the sleep monitoring signal to output an optimized signal and a feature extraction unit connected to the preprocessing unit for extracting the features of the optimized signal to output physiological signal features. Among them, the preprocessing unit includes a filter for filtering the sleep monitoring signal;

[0031] An analysis module, which is connected to the signal processing module, for analyzing the sleep monitoring signal and the physiological signal features to output a sleep state analysis result;

[0032] A storage module, which is respectively connected to the signal acquisition module, the signal processing module, and the analysis module, for respectively storing the sleep monitoring signal, the optimized signal, the physiological signal features, and the sleep state analysis result;

[0033] A control module, which is respectively connected to the signal acquisition module, the signal processing module, the analysis module, and the storage module, for determining the center frequency of the millimeter-wave radar according to the change amount of the signal-to-noise ratio of the sleep monitoring signal, or for determining the cut-off frequency of the filter according to the fluctuation amplitude of the sleep monitoring signal, and for determining the clock frequency of the millimeter-wave radar according to the working frequency offset amount of the millimeter-wave radar per unit time.

[0034] Specifically, the sleep monitoring signal includes respiratory frequency, heartbeat amplitude, and body movement times.

[0035] Specifically, the optimized signals include the amplified breathing frequency signal, the enhanced heartbeat amplitude signal, and the prominent body movement count signal.

[0036] Specifically, the physiological signal features include the breathing frequency feature, the heartbeat amplitude feature, and the body movement frequency feature.

[0037] Specifically, the preprocessing unit further includes an amplifier for amplifying the sleep monitoring signal.

[0038] Specifically, the sleep state analysis results include the light sleep stage, the deep sleep stage, and the rapid eye movement sleep stage.

[0039] In implementation, the device of the present invention determines the center frequency of the millimeter-wave radar according to the change amount of the signal-to-noise ratio of the sleep monitoring signal by setting a signal acquisition module, a signal processing module, an analysis module, a storage module, and a control module. Since in the environment where the millimeter-wave radar operates, it may be interfered by WiFi signals, resulting in harmonics, thus making the radar signal unstable. By increasing the center frequency of the millimeter-wave radar, the interference signals received by the millimeter-wave radar can be reduced, thereby improving the signal stability. The cut-off frequency of the filter is determined according to the fluctuation amplitude of the sleep monitoring signal. Since the body micro-movement signal becomes complex due to the change of the human sleep posture during signal acquisition, resulting in inaccurate extraction of features during feature extraction. By reducing the cut-off frequency of the filter, it can be ensured that while filtering out noise, the useful low-frequency signal components will not be filtered out, so that the body micro-movement signal features with reduced frequency due to posture change can be accurately extracted. The clock frequency of the millimeter-wave radar is determined according to the working frequency offset amount of the millimeter-wave radar per unit time. Since the internal components of the millimeter-wave radar age after long-term operation, resulting in a decline in the performance of the internal oscillator, thus causing the working frequency of the millimeter-wave radar to shift. By reducing the clock frequency of the millimeter-wave radar, the signal processing can be rematched with the reduced working frequency, ensuring the accuracy of signal processing and improving the monitoring stability of the sleep monitoring device.

[0040] Specifically, the control module is used to obtain the signal-to-noise ratio of the sleep monitoring signal within a single period and calculate the change amount of the signal-to-noise ratio of the sleep monitoring signal. If the change amount of the signal-to-noise ratio of the sleep monitoring signal is greater than a preset first change amount, it is determined that the monitoring stability of the sleep monitoring device does not meet the requirements.

[0041] Specifically, when the change amount of the signal-to-noise ratio of the sleep monitoring signal is greater than the preset first change amount and less than or equal to the preset second change amount, the control module preliminarily determines that the accuracy of sleep monitoring does not meet the requirements and determines whether the accuracy of sleep monitoring meets the requirements according to the fluctuation amplitude of the sleep monitoring signal.

[0042] It can be understood that the three intervals divided by the preset first change amount and the preset second change amount respectively correspond to three situations:

[0043] The first interval is that the change amount of the signal-to-noise ratio of the sleep monitoring signal is less than or equal to the preset first change amount, and the corresponding situation is: it is determined that the monitoring stability of the sleep monitoring device meets the requirements;

[0044] The second interval is that the change amount of the signal-to-noise ratio of the sleep monitoring signal is greater than the preset first change amount and less than or equal to the preset second change amount, and the corresponding situation is: due to the change of the human body's sleep posture during signal acquisition, the micro-motion signal of the human body becomes complex, resulting in inaccurate feature extraction;

[0045] The third interval is that the change amount of the signal-to-noise ratio of the sleep monitoring signal is greater than the preset second change amount, and the corresponding situation is: in the environment where the millimeter-wave radar works, it may be interfered by the WiFi signal, resulting in harmonics, thus making the radar signal unstable.

[0046] In practice, the generally selected range of the preset first change amount is [8 dB, 12 dB], and the generally selected range of the preset second change amount is [13 dB, 17 dB].

[0047] Preferably, the preferred embodiment of the preset first change amount is 10 dB, and the preferred embodiment of the preset second change amount is 15 dB.

[0048] Specifically, the change amount of the signal-to-noise ratio of the sleep monitoring signal is the difference between the maximum signal-to-noise ratio and the minimum signal-to-noise ratio of the sleep monitoring signal within a single period.

[0049] In implementation, the device of the present invention determines the monitoring stability of the sleep monitoring device by setting the preset first change amount and the preset second change amount, reducing the impact of the inaccurate determination of the monitoring stability of the sleep monitoring device on the monitoring accuracy of the sleep monitoring device, and further improving the monitoring stability of the sleep monitoring device.

[0050] Specifically, the control module is used to increase the center frequency of the millimeter-wave radar when the change amount of the signal-to-noise ratio of the sleep monitoring signal is greater than the preset second change amount;

[0051] Wherein, the increase amplitude of the center frequency of the millimeter-wave radar is determined by the difference between the change amount of the signal-to-noise ratio of the sleep monitoring signal and the preset second change amount.

[0052] Specifically, when the difference between the change amount of the signal-to-noise ratio of the sleep monitoring signal and the preset second change amount is within 3 dB, the center frequency of the millimeter-wave radar increases to 1.2 times the original; when the difference between the change amount of the signal-to-noise ratio of the sleep monitoring signal and the preset second change amount exceeds 3 dB, on the basis of increasing to 1.2 times the original, for every 2 dB exceeded, the center frequency of the millimeter-wave radar increases by 2 GHz. For example, if the difference between the change amount of the signal-to-noise ratio of the sleep monitoring signal and the preset second change amount is 7 dB and the current center frequency of the millimeter-wave radar is 60 GHz, the increased center frequency of the millimeter-wave radar is 60×1.2 + 2×2 = 76 GHz.

[0053] Specifically, GHz is the unit of the center frequency of the millimeter-wave radar, and its meaning is gigahertz.

[0054] In implementation, the device of the present invention determines the center frequency of the millimeter-wave radar by setting a preset first change amount and a preset second change amount. Since in the environment where the millimeter-wave radar operates, it may be interfered by WiFi signals, resulting in harmonics, thus making the radar signal unstable. By increasing the center frequency of the millimeter-wave radar, the interference signals received by the millimeter-wave radar can be reduced, thereby improving the signal stability and further improving the monitoring stability of the sleep monitoring device.

[0055] Specifically, the control module is used to obtain the sleep monitoring signal within a single period and calculate the fluctuation amplitude of the sleep monitoring signal. If the fluctuation amplitude of the sleep monitoring signal is greater than the preset first fluctuation amplitude, it is determined that the accuracy of sleep monitoring does not meet the requirements.

[0056] Specifically, when the fluctuation amplitude of the sleep monitoring signal is greater than the preset second fluctuation amplitude, the control module preliminarily determines that the working performance of the millimeter-wave radar does not meet the requirements, and determines whether the working performance of the millimeter-wave radar meets the requirements according to the working frequency offset amount of the millimeter-wave radar per unit time.

[0057] It can be understood that the three intervals divided by the preset first fluctuation amplitude and the preset second fluctuation amplitude respectively correspond to three situations:

[0058] The first interval is that the fluctuation amplitude of the sleep monitoring signal is less than or equal to the preset first fluctuation amplitude, and the corresponding situation is: it is determined that the accuracy of sleep monitoring meets the requirements;

[0059] The second interval is that the fluctuation amplitude of the sleep monitoring signal is greater than the preset first fluctuation amplitude and less than or equal to the preset second fluctuation amplitude, and the corresponding situation is: due to the change of the human body's sleep posture during signal acquisition, the human body's micro-motion signals become complex, resulting in inaccurate feature extraction;

[0060] The third interval is that the fluctuation amplitude of the sleep monitoring signal is greater than a preset second fluctuation amplitude, and the corresponding situation is that after the millimeter-wave radar has been working for a long time, the internal components age, resulting in a decline in the performance of the internal oscillator, and thus causing the operating frequency of the millimeter-wave radar to shift.

[0061] In practice, the generally selected range of the preset first fluctuation amplitude is [3mm, 5mm], and the generally selected range of the preset second fluctuation amplitude is [6mm, 8mm].

[0062] Preferably, the preferred embodiment of the preset first fluctuation amplitude is 4mm, and the preferred embodiment of the preset second fluctuation amplitude is 7mm.

[0063] Specifically, the fluctuation amplitude of the sleep monitoring signal is the fluctuation amplitude of the breathing signal in the sleep state.

[0064] Specifically, the fluctuation amplitude of the sleep monitoring signal is the difference between the maximum value and the minimum value of the sleep monitoring signal within a single period.

[0065] In implementation, the device of the present invention determines the accuracy of sleep monitoring by setting the preset first fluctuation amplitude and the preset second fluctuation amplitude, reducing the impact of the decline in the monitoring stability of the sleep monitoring device caused by inaccurate determination of the accuracy of sleep monitoring, and further improving the monitoring stability of the sleep monitoring device.

[0066] Specifically, when the fluctuation amplitude of the sleep monitoring signal is greater than the preset first fluctuation amplitude and less than or equal to the preset second fluctuation amplitude, the control module reduces the cut-off frequency of the filter.

[0067] Specifically, the reduction amplitude of the cut-off frequency of the filter is determined by the difference between the fluctuation amplitude of the sleep monitoring signal and the preset first fluctuation amplitude.

[0068] Specifically, when the difference between the fluctuation amplitude of the sleep monitoring signal and the preset first fluctuation amplitude is within 2mm, the cut-off frequency of the filter is reduced to 0.9 times the original; when the difference between the fluctuation amplitude of the sleep monitoring signal and the preset first fluctuation amplitude exceeds 2mm, on the basis of reducing to 0.9 times the original, for every 1mm exceeded, the cut-off frequency of the filter is reduced by 1Hz. For example, if the difference between the fluctuation amplitude of the sleep monitoring signal and the preset first fluctuation amplitude is 4mm, and the current cut-off frequency of the filter is 20Hz, the reduced cut-off frequency of the filter is 20×0.9 - 1×2 = 16Hz.

[0069] In implementation, the device of the present invention determines the cut-off frequency of the filter by setting a preset first fluctuation amplitude and a preset second fluctuation amplitude. Since the human body micro-motion signal becomes complex due to the change of the human body's sleeping posture during signal acquisition, it leads to inaccurate extraction of features during feature extraction. By reducing the cut-off frequency of the filter, it can ensure that while filtering noise, useful low-frequency signal components will not be filtered out, so that the features of the human body micro-motion signal whose frequency becomes lower due to posture change can be accurately extracted, further improving the monitoring stability of the sleep monitoring device.

[0070] Specifically, the control module is used to obtain the operating frequency of the millimeter-wave radar within a unit time and calculate the offset of the operating frequency of the millimeter-wave radar within a unit time. If the offset of the operating frequency of the millimeter-wave radar within a unit time is greater than the preset offset, it is determined that the operating performance of the millimeter-wave radar does not meet the requirements, and the clock frequency of the millimeter-wave radar is reduced.

[0071] It can be understood that the two intervals divided by the preset offset respectively correspond to two situations:

[0072] The first interval is that the offset of the operating frequency of the millimeter-wave radar within a unit time is less than or equal to the preset offset, and the corresponding situation is: it is determined that the operating performance of the millimeter-wave radar meets the requirements;

[0073] The second interval is that the offset of the operating frequency of the millimeter-wave radar within a unit time is greater than the preset offset, and the corresponding situation is: due to the aging of internal components after the long-term operation of the millimeter-wave radar, the performance of the internal oscillator decreases, resulting in the offset of the operating frequency of the millimeter-wave radar.

[0074] In practice, the generally selected range of the preset offset is [1 MHz / s, 3 MHz / s].

[0075] Preferably, the preferred embodiment of the preset offset is 2 MHz / s.

[0076] Specifically, MHz is the offset of the operating frequency of the millimeter-wave radar within a unit time, and its meaning is megahertz per second.

[0077] In implementation, the device of the present invention determines the operating performance of the millimeter-wave radar by setting a preset offset, reducing the impact of the inaccurate determination of the operating performance of the millimeter-wave radar on the reduction of the monitoring stability of the sleep monitoring device, and further improving the monitoring stability of the sleep monitoring device.

[0078] Specifically, the reduction amplitude of the clock frequency of the millimeter-wave radar is determined by the difference between the offset of the operating frequency of the millimeter-wave radar within a unit time and the preset offset.

[0079] Specifically, when the difference between the working frequency offset of the millimeter-wave radar per unit time and the preset offset is within 1 MHz / s, the clock frequency of the millimeter-wave radar is reduced to 0.92 times the original; when the difference between the working frequency offset of the millimeter-wave radar per unit time and the preset offset exceeds 1 MHz / s, on the basis of being reduced to 0.92 times the original, for every 0.5 MHz / s exceeded, the clock frequency of the millimeter-wave radar is reduced by 3 MHz. For example, when the difference between the working frequency offset of the millimeter-wave radar per unit time and the preset offset is 2 MHz / s, and the current clock frequency of the millimeter-wave radar is 50 MHz, the reduced clock frequency of the millimeter-wave radar is 50×0.92 - 3×2 = 40 MHz.

[0080] In implementation, the device of the present invention determines the clock frequency of the millimeter-wave radar by setting a preset offset. Since the internal components of the millimeter-wave radar age after long-term operation, the performance of the internal oscillator deteriorates, resulting in an offset of the working frequency of the millimeter-wave radar. By reducing the clock frequency of the millimeter-wave radar, the signal processing can be rematched with the reduced working frequency, ensuring the accuracy of signal processing and further improving the monitoring stability of the sleep monitoring device.

[0081] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A sleep monitoring device based on millimeter wave radar, characterized in that: include: A signal acquisition module is used to receive the sleep monitoring signal transmitted by the millimeter-wave radar and reflected back; a signal processing module connected to the signal acquisition module, comprising a preprocessing unit for preprocessing the sleep monitoring signal to output an optimized signal and a feature extraction unit connected to the preprocessing unit for extracting features of the optimized signal to output physiological signal features, wherein the preprocessing unit comprises a filter for filtering the sleep monitoring signal; An analysis module, connected to the signal processing module, for analyzing the sleep monitoring signal and the physiological signal characteristics to output a sleep state analysis result; A storage module, which is connected to the signal acquisition module, the signal processing module and the analysis module respectively, and is used to store the sleep monitoring signal, the optimization signal, the physiological signal feature and the sleep state analysis result respectively; A control module, which is respectively connected to the signal acquisition module, the signal processing module, the analysis module and the storage module, and is used to determine the center frequency of the millimeter wave radar according to the change in the signal-to-noise ratio of the sleep monitoring signal, or to determine the cutoff frequency of the filter according to the fluctuation amplitude of the sleep monitoring signal, and to determine the clock frequency of the millimeter wave radar according to the working frequency offset of the millimeter wave radar per unit time; The increase amplitude of the center frequency of the millimeter wave radar is determined by the difference between the signal-to-noise ratio change of the sleep monitoring signal and the preset second change; When the difference between the signal-to-noise ratio change of the sleep monitoring signal and the preset second change is within 3dB, the center frequency of the millimeter-wave radar is increased to 1.2 times the original value; when the difference between the signal-to-noise ratio change of the sleep monitoring signal and the preset second change exceeds 3dB, on the basis of increasing to 1.2 times the original value, the center frequency of the millimeter-wave radar is increased by 2GHz for every 2dB exceeding the limit; The reduction amplitude of the cutoff frequency of the filter is determined by the difference between the fluctuation amplitude of the sleep monitoring signal and the preset first fluctuation amplitude; When the difference between the fluctuation amplitude of the sleep monitoring signal and the preset first fluctuation amplitude is within 2mm, the cutoff frequency of the filter is reduced to 0.9 times of the original value; when the difference between the fluctuation amplitude of the sleep monitoring signal and the preset first fluctuation amplitude exceeds 2mm, on the basis of being reduced to 0.9 times of the original value, the cutoff frequency of the filter is reduced by 1Hz for every 1mm exceeding the limit; The reduction amplitude of the clock frequency of the millimeter wave radar is determined by the difference between the working frequency offset of the millimeter wave radar and the preset offset per unit time; When the difference between the operating frequency offset of the millimeter-wave radar and the preset offset per unit time is within 1MHz / s, the clock frequency of the millimeter-wave radar is reduced to 0.92 times of the original; when the difference between the operating frequency offset of the millimeter-wave radar and the preset offset per unit time exceeds 1MHz / s, on the basis of being reduced to 0.92 times of the original, the clock frequency of the millimeter-wave radar is reduced by 3MHz for every 0.5MHz / s that exceeds it.

2. The sleep monitoring device based on millimeter wave radar according to claim 1, characterized in that: The control module is used to determine whether the monitoring stability of the sleep monitoring device meets the requirements according to the signal-to-noise ratio change of the sleep monitoring signal. If the signal-to-noise ratio change of the sleep monitoring signal is greater than a preset first change, it is determined that the monitoring stability of the sleep monitoring device does not meet the requirements.

3. The sleep monitoring device based on millimeter wave radar according to claim 2, characterized in that: The control module is used to preliminarily determine that the accuracy of sleep monitoring does not meet the requirements when the signal-to-noise ratio change of the sleep monitoring signal is greater than the preset first change and less than or equal to the preset second change, and determine whether the accuracy of sleep monitoring meets the requirements based on the fluctuation amplitude of the sleep monitoring signal.

4. The millimeter wave radar-based sleep monitoring device according to claim 3, characterized in that: The control module is used to increase the center frequency of the millimeter wave radar when the signal-to-noise ratio change of the sleep monitoring signal is greater than the preset second change.

5. The millimeter wave radar-based sleep monitoring device according to claim 4, characterized in that: The control module is used to determine whether the accuracy of sleep monitoring meets the requirements according to the fluctuation amplitude of the sleep monitoring signal. If the fluctuation amplitude of the sleep monitoring signal is greater than a preset first fluctuation amplitude, it is determined that the accuracy of sleep monitoring does not meet the requirements.

6. The millimeter wave radar-based sleep monitoring device according to claim 5, characterized in that: When the fluctuation amplitude of the sleep monitoring signal is greater than a preset second fluctuation amplitude, the control module preliminarily determines that the working performance of the millimeter-wave radar does not meet the requirements, and determines whether the working performance of the millimeter-wave radar meets the requirements based on the working frequency offset of the millimeter-wave radar per unit time.

7. The millimeter wave radar-based sleep monitoring device according to claim 6, characterized in that: The control module reduces the cutoff frequency of the filter when the fluctuation amplitude of the sleep monitoring signal is greater than the preset first fluctuation amplitude and less than or equal to the preset second fluctuation amplitude.

8. The millimeter wave radar-based sleep monitoring device according to claim 7, characterized in that: The control module is used to determine whether the working performance of the millimeter-wave radar meets the requirements according to the working frequency offset of the millimeter-wave radar in unit time. If the working frequency offset of the millimeter-wave radar in the unit time is greater than the preset offset, it is determined that the working performance of the millimeter-wave radar does not meet the requirements, and the clock frequency of the millimeter-wave radar is reduced.

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