阅读说明：本技术 生命体征的检测装置、方法及系统 (Detection device, method and system for vital signs ) 是由 李红春 谢莉莉 赵倩 田军 于 2019-08-16 设计创作，主要内容包括：本发明实施例提供一种生命体征的检测装置、方法及系统,该装置包括：第一计算单元,其根据第一预设时间范围内的微波雷达的反射信号,计算生命体所在位置的距离FFT信号的随时间变化的相位分布；展开单元,其用于对相位分布进行相位展开；第一确定单元,其用于根据预设的时间窗,确定经过相位展开的相位分布的所有局部极值点,时间窗是根据生命体的呼吸或心跳的周期范围而确定的；均匀化单元,其用于对每一对相邻局部极值点之间的相位分布进行幅值的均匀化处理；以及第二计算单元,其用于根据经过幅值的均匀化处理的相位分布,计算生命体的呼吸或心跳的频率。(The embodiment of the invention provides a device, a method and a system for detecting vital signs, wherein the device comprises: the first calculation unit is used for calculating the phase distribution of the distance FFT signal of the position of the living body along with the change of time according to the reflected signal of the microwave radar in a first preset time range; an unwrapping unit for phase unwrapping the phase distribution; a first determining unit configured to determine all local extreme points of the phase distribution subjected to the phase unwrapping according to a preset time window, the time window being determined according to a cycle range of respiration or heartbeat of a living body; the uniformization unit is used for performing amplitude uniformization processing on the phase distribution between each pair of adjacent local extreme points; and a second calculation unit for calculating the frequency of breathing or heartbeat of the living body based on the phase distribution subjected to the uniformization processing of the amplitude.)

1. A vital sign detection apparatus, the apparatus comprising:

the first calculation unit is used for calculating the phase distribution of the distance Fast Fourier Transform (FFT) signal of the position of the living body along with the change of time according to the reflected signal of the microwave radar in a first preset time range;

an unwrapping unit for phase unwrapping the phase distribution;

a first determining unit, configured to determine all local extreme points of the phase distribution subjected to phase unwrapping according to a preset time window, where the time window is determined according to a cycle range of respiration or heartbeat of the living body;

the uniformization unit is used for performing amplitude uniformization processing on the phase distribution between each pair of adjacent local extreme points; and

a second calculation unit for calculating a frequency of respiration or heartbeat of the living body based on the phase distribution subjected to the uniformization of the amplitude value.

2. The apparatus of claim 1, wherein,

the first determination unit shifts the time windows on the time axis of the phase-unwrapped phase distribution, determines whether or not there is a local extreme point in each time window, and thereby obtains all local extreme points on the entire phase-unwrapped phase distribution.

3. The apparatus of claim 1, wherein,

the width of the time window is an integral multiple of a lower limit value of a periodic range of respiration or heartbeat of the living body.

4. The apparatus of claim 1, wherein,

the local extreme point is a local maximum point or a local minimum point,

the homogenizing unit includes:

a second determination unit for determining a point having a minimum magnitude between adjacent first and second local maximum points, or determining a point having a maximum magnitude between adjacent first and second local minimum points; and

a regularization unit for regularizing the first local maximum point and the point of minimum amplitude and the second local maximum point when both a first time interval between the point of minimum amplitude and the second local maximum point are less than a preset threshold, regularizing a phase distribution between the first local maximum point and the point where the amplitude is minimum and between the point where the amplitude is minimum and the second local maximum point, or, when a third time interval between the first local minimum point and the point with the maximum amplitude and a fourth time interval between the point with the maximum amplitude and the second local minimum point are both smaller than the preset threshold value, and regularizing the phase distribution between the first local minimum point and the point with the maximum amplitude and between the point with the maximum amplitude and the second local minimum point.

5. The apparatus of claim 4, wherein,

the preset threshold is determined according to an upper limit value of a cycle range of respiration or heartbeat of the living body.

6. The apparatus of claim 1, wherein the second computing unit comprises:

a filtering unit for performing band-pass filtering on the phase distribution subjected to the homogenization treatment of the amplitude; and

a third calculation unit for calculating a frequency of respiration or heartbeat of the living body from the band-pass filtered phase distribution.

7. The apparatus of claim 6, wherein the third computing unit comprises:

a counting unit for counting the number of local extreme points in the bandpass-filtered phase distribution within a second preset time range; and

and the fourth calculating unit is used for calculating the breathing or heartbeat frequency of the life body according to the counted number of the extreme points.

8. A vital signs detection system, comprising:

a microwave radar having a signal transmitting unit that transmits a microwave signal to a space where a living body is located and a signal receiving unit that receives a reflected signal; and

detection apparatus of vital signs according to claim 1, which performs vital sign detection from the reflected signal.

9. A method of vital sign detection, the method comprising:

calculating the phase distribution of the distance Fast Fourier Transform (FFT) signal of the position of the living body along with the time change according to the reflected signal of the microwave radar in the first preset time range;

performing phase unwrapping on the phase distribution;

determining all local extreme points of the phase distribution subjected to phase unwrapping according to a preset time window, wherein the time window is determined according to the periodic range of respiration or heartbeat of the living body;

carrying out amplitude homogenization treatment on the phase distribution between each pair of adjacent local extreme points; and

and calculating the frequency of the respiration or heartbeat of the living body according to the phase distribution subjected to the amplitude homogenization treatment.

10. The method of claim 9, wherein determining all local extreme points of the phase unwrapped phase profile according to a preset time window comprises:

shifting the time windows on the time axis of the phase unwrapped phase profile, and determining whether each time window has a local extreme point, thereby obtaining all local extreme points on the entire phase unwrapped phase profile.

Technical Field

The invention relates to the technical field of information.

Background

Monitoring vital signs such as respiration and heartbeat is helpful for understanding the physical health condition of human body. In medicine, people use specialized medical equipment such as an electrocardiograph detector and a stethoscope to obtain the information of the breath and the heartbeat of a patient. With the advancement of technology, wearable devices are emerging in large numbers; people can monitor the body index change of people at any time in daily life by utilizing equipment such as an intelligent watch and an intelligent bracelet. However, popularization and application of wearable devices face problems of low wearing comfort, frequent charging and the like.

In recent years, a non-contact vital sign detection method has appeared, for example, a vital sign detection method based on a microwave radar that performs detection of breathing and heartbeat by collecting a microwave signal reflected by a detection object by the microwave radar. The method has the advantages of good user experience, high acceptance and wide application prospect.

It should be noted that the above background description is only for the sake of clarity and complete description of the technical solutions of the present invention and for the understanding of those skilled in the art. Such solutions are not considered to be known to the person skilled in the art merely because they have been set forth in the background section of the invention.

Disclosure of Invention

However, the inventor found that, since the radar signal is very sensitive and is easily interfered by noise during propagation, for example, the moving or jogging of a living body, radar signals reflected by other objects, respiratory harmonics, and the like may cause noise to be generated, thereby affecting the detection accuracy, the detection accuracy is poor by using the existing vital sign detection method based on microwave radar.

The embodiment of the invention provides a device, a method and a system for detecting vital signs, which can enhance signal fluctuation caused by respiration or heartbeat of a detected object and homogenize the fluctuation by determining local extreme points of phase distribution of a distance fast Fourier transform signal along with time change and carrying out amplitude homogenization treatment on signals between each pair of adjacent local extreme points, thereby eliminating the influence of noise caused by factors such as movement or micromotion of a living body, radar signals reflected by other objects, respiratory harmonics and the like and obtaining higher detection precision.

According to a first aspect of embodiments of the present invention, there is provided a device for vital sign detection, the device comprising: the first calculation unit is used for calculating the phase distribution of the distance Fast Fourier Transform (FFT) signal of the position of the living body along with the change of time according to the reflected signal of the microwave radar in a first preset time range; an unwrapping unit for phase unwrapping the phase distribution; a first determining unit, configured to determine all local extreme points of the phase distribution subjected to phase unwrapping according to a preset time window, where the time window is determined according to a cycle range of respiration or heartbeat of the living body; the uniformization unit is used for performing amplitude uniformization processing on the phase distribution between each pair of adjacent local extreme points; and a second calculation unit for calculating the frequency of breathing or heartbeat of the living body based on the phase distribution subjected to the uniformization processing of the amplitude.

According to a second aspect of embodiments of the present invention, there is provided a vital signs detection system, comprising: a microwave radar having a signal transmitting unit that transmits a microwave signal to a space where a living body is located and a signal receiving unit that receives a reflected signal; and the vital sign detection device according to the first aspect of the embodiment of the present invention, which detects the vital sign according to the reflected signal.

According to a third aspect of embodiments of the present invention, there is provided a method of detecting a vital sign, the method including: calculating a distance Fast Fourier Transform (FFT) signal of the position of the living body according to a reflected signal of the microwave radar within a first preset time range; performing phase unwrapping on the phase distribution; determining all local extreme points of the phase distribution subjected to phase unwrapping according to a preset time window, wherein the time window is determined according to the periodic range of respiration or heartbeat of the living body; carrying out amplitude homogenization treatment on the phase distribution between each pair of adjacent local extreme points; and calculating the frequency of respiration or heartbeat of the living body according to the phase distribution subjected to the amplitude homogenization treatment.

The invention has the beneficial effects that: by determining the local extreme points of the time-varying phase distribution of the range fast Fourier transform signal and performing amplitude homogenization processing on the signal between each pair of adjacent local extreme points, signal fluctuation caused by respiration or heartbeat serving as a detection object can be enhanced and homogenized, so that the influence of noise caused by factors such as movement or micromotion of a living body, radar signals reflected by other objects, respiratory harmonics and the like can be eliminated, and high detection accuracy is obtained.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not so limited in scope. The embodiments of the invention include many variations, modifications and equivalents within the spirit and scope of the appended claims.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

fig. 1 is a schematic view of a vital sign detection apparatus according to embodiment 1 of the present invention;

fig. 2 is a schematic diagram of signals transmitted and received by the microwave radar of embodiment 1 of the present invention;

FIG. 3 is a schematic view of a graph of the phase distribution before phase unwrapping in embodiment 1 of the present invention;

FIG. 4 is a schematic diagram of a phase distribution curve after phase unwrapping according to embodiment 1 of the present invention;

FIG. 5 is a schematic view of the homogenizing unit 104 according to embodiment 1 of the present invention;

FIG. 6 is a schematic diagram of a method for homogenizing the amplitude of a phase distribution between two adjacent local maximum points according to embodiment 1 of the present invention;

FIG. 7 is a schematic view of a graph of the homogenized phase distribution obtained in the breath detection in example 1 of the present invention;

FIG. 8 is a schematic view of a graph of the homogenized phase distribution obtained in the heartbeat detection in example 1 of the present invention;

FIG. 9 is a diagram of the second calculating unit 105 according to embodiment 1 of the present invention;

FIG. 10 is a schematic diagram of a curve obtained by band-pass filtering the homogenized phase distribution obtained in the breath detection shown in FIG. 7 according to embodiment 1 of the present invention;

fig. 11 is a schematic diagram of a curve obtained by band-pass filtering the homogenized phase distribution obtained in detecting the heartbeat shown in fig. 8 according to embodiment 1 of the present invention;

fig. 12 is a schematic diagram of the third computing unit 902 according to embodiment 1 of the present invention;

fig. 13 is a schematic view of an electronic device according to embodiment 2 of the present invention;

fig. 14 is a schematic block diagram of a system configuration of an electronic apparatus according to embodiment 2 of the present invention;

fig. 15 is a schematic view of a vital sign detection system according to embodiment 3 of the present invention;

fig. 16 is a schematic diagram of a vital sign detection method according to embodiment 4 of the present invention.

Detailed Description

The foregoing and other features of the invention will become apparent from the following description taken in conjunction with the accompanying drawings. In the description and drawings, particular embodiments of the invention have been disclosed in detail as being indicative of some of the embodiments in which the principles of the invention may be employed, it being understood that the invention is not limited to the embodiments described, but, on the contrary, is intended to cover all modifications, variations, and equivalents falling within the scope of the appended claims.

Example 1

The present embodiment provides a vital sign detection apparatus, and fig. 1 is a schematic diagram of the vital sign detection apparatus according to embodiment 1 of the present invention. As shown in fig. 1, the vital sign detection apparatus 100 includes:

a first calculating unit 101, configured to calculate a time-varying phase distribution of a Fast Fourier Transform (FFT) signal of a position where a living object is located according to a reflected signal of the microwave radar within a first preset time range;

an unwrapping unit 102 for phase unwrapping the phase distribution;

a first determining unit 103, configured to determine all local extreme points of the phase distribution subjected to phase unwrapping according to a preset time window, where the time window is determined according to a cycle range of respiration or heartbeat of the living body;

a uniformizing unit 104 for performing an amplitude uniformizing process on the phase distribution between each pair of adjacent local extreme points; and

a second calculating unit 105 for calculating the frequency of respiration or heartbeat of the living body based on the phase distribution subjected to the uniformization of the amplitude.

As can be seen from the above-described embodiments, by determining local extreme points of the time-varying phase distribution of the range fast fourier transform signal and performing amplitude equalization processing on the signal between each pair of adjacent local extreme points, it is possible to enhance and equalize signal fluctuations caused by respiration or heartbeat as a detection target, thereby eliminating the influence of noise caused by factors such as movement or micromotion of a living body, radar signals reflected by other objects, and respiratory harmonics, and obtaining high detection accuracy.

In this embodiment, the vital sign detection apparatus can be used for detecting vital signs of various living bodies. In this example, a human body is exemplified as a detection target.

In this embodiment, the vital sign may include heartbeat or respiration. For example, the vital sign detection device may detect respiration of a living body, may detect heartbeat of the living body, or may detect respiration and heartbeat of the living body separately.

The first calculation unit 101 calculates a distance FFT signal of a position where the living body is located according to a reflected signal of the microwave radar within a first preset time range, and obtains a time-varying phase distribution of the distance FFT signal, which can be represented by a time-varying phase curve.

In this embodiment, the first preset time range at least includes one period of breathing or heartbeat, and the specific range thereof can be set according to actual needs.

For example, taking a human body as an example, the period of respiration may be 3 to 6 seconds, and the period of heartbeat may be 0.3 to 1.2 seconds.

In this embodiment, the microwave radar may be a microwave radar with a Frequency Modulated Continuous Wave (FMCW) operation mode. The transmitted signal of the microwave radar is reflected by the object including the human body and then received by the microwave radar. The microwave radar processes the transmitted signal and the received reflected signal to obtain a difference frequency signal. The signals received by the microwave radar are the superposition of all reflected signals in the space, and the signals can be decomposed by performing fast Fourier transform on the difference frequency signals to obtain the reflected signals at different distances, wherein the Fourier transform is called distance FFT (Range FFT). The range FFT signal obtained after the range FFT processing can be expressed by the following equation (1):

S＝Asin(2πft+p) (1)

wherein, a is amplitude, p is phase, frequency f is affected by the distance between the human body and the radar, f is s2d/c, s is the slope of frequency modulation of the microwave radar transmitting signal, d is the distance between the human body and the radar, and c is the speed of light.

Fig. 2 is a schematic diagram of signals transmitted and received by the microwave radar according to embodiment 1 of the present invention. When the human body is at rest, the change of the phase p of the distance FFT signal reflects the micromotion of the human body. Both the respiration and the heartbeat of a person cause a micromotion of the body. As shown in FIG. 2, assuming that the distance between the human body and the radar is d and only the micro-motion caused by respiration, the FFT signal corresponding to d during inspiration is S according to the above formula (1)₀＝Asin(2πft+p₀) The distance FFT signal corresponding to d' during expiration is S₁＝Asin(2πft+p₁)。

The phase difference Δ p of the distance FFT signals at the time of inhalation and exhalation is related to the displacement Δ d of the thoracic cavity caused by respiration or heartbeat, and can be expressed by the following formula (2) according to the distance FFT signals corresponding to d at the time of inhalation and exhalation:

Δp＝4πΔd/λ (2)

wherein λ is the wavelength of the microwave radar signal, and Δ d is the displacement of the thoracic cavity caused by respiration or heartbeat.

Therefore, by analyzing the phase distribution of the distance FFT signal changing along with time, the rule of the micro-motion change of the human body can be obtained, and further the frequency of breathing or heartbeat can be obtained.

In the present embodiment, after the first calculation unit 101 obtains a time-varying phase distribution of the distance FFT signal at the position where the human body is present, the phase distribution is subjected to phase unwrapping by the unwrapping unit 102. Various phase unwrapping methods can be used, for example, phase unwrapping at a time of a phase jump.

The Phase Unwrapping (Phase Unwrapping) of the present embodiment can be implemented by adding or subtracting 2 pi to the Phase value according to the Phase difference between the adjacent Phase values in an ideal case.

Fig. 3 is a schematic diagram of a curve of a phase distribution before phase unwrapping in embodiment 1 of the present invention, and fig. 4 is a schematic diagram of a curve of a phase distribution after phase unwrapping in embodiment 1 of the present invention. As shown in fig. 3 and 4, the abscissa of the phase distribution is time in seconds, and the ordinate is phase in radians, and after phase expansion, the phase distribution becomes smooth, and abnormal abrupt phase changes are eliminated. As shown in fig. 4, the more pronounced fluctuations in the phase distribution are due to respiration, while the smaller fluctuations in these fluctuations are due to the heartbeat, e.g., the fluctuations shown in a are due to respiration and the fluctuations shown in B are due to the heartbeat.

In the present embodiment, after the phase unwrapping unit 102 performs the phase unwrapping on the phase distribution, the first determining unit 103 determines all local extreme points of the phase unwrapped phase distribution according to a preset time window,

for example, the first determination unit 103 shifts time windows on the time axis of the phase-unwrapped phase distribution, determines whether or not there is a local extreme point within each time window, and thereby obtains all local extreme points on the entire phase-unwrapped phase distribution.

For example, the first determination unit 103 smoothly shifts the time window on the time axis over the entire time range of the phase distribution subjected to the phase unwrapping to determine all the local extreme points.

In this embodiment, the time window is determined according to the range of cycles of the respiration or heartbeat of the living being. For example, the width of the time window is an integral multiple of the lower limit value of the periodic range of the respiration or heartbeat of the human body. For example, the width of the time window is 2 times the lower limit value.

For example, when the detection object is a respiratory frequency, the time window is determined according to a respiratory cycle range, the respiratory cycle can be 3-6 seconds, and therefore, the lower limit value T of the respiratory cycle range_L3 seconds, upper limit value T_HIt was 6 seconds. In this case, the width of the time window may be 6 seconds.

For another example, when the detection object is a heartbeat frequency, the time window is determined according to a period range of the heartbeat, and the period of the heartbeat can be 0.3 to 1.2 seconds, so that the lower limit value T of the period range of the heartbeat_L0.3 second, upper limit value T_HIt was 1.2 seconds. In this case, the width of the time window may be 0.6 seconds.

In this embodiment, the local extreme point may be a local maximum point or a local minimum point, and the first determining unit 103 only needs to determine one of the extreme points.

In the present embodiment, after the first determination unit 103 determines all the local extreme points of the phase distribution subjected to the phase unwrapping, the uniformizing unit 104 performs the uniformizing process of the amplitude of the phase distribution between each pair of adjacent local extreme points.

In this embodiment, various homogenization treatment methods can be used, and the embodiment of the present invention does not limit the specific method of homogenization treatment.

FIG. 5 is a schematic view of the uniformizing unit 104 according to embodiment 1 of the present invention. As shown in fig. 5, the uniformizing unit 104 includes:

a second determining unit 501, configured to determine a point with a minimum amplitude between adjacent first and second local maximum points, or determine a point with a maximum amplitude between adjacent first and second local minimum points; and

a regularization unit 502 configured to regularize a phase distribution between the first local maximum point and the point with the minimum amplitude and between the point with the minimum amplitude and the second local maximum point when both a first time interval between the first local maximum point and the point with the minimum amplitude and a second time interval between the point with the minimum amplitude and the second local maximum point are smaller than a preset threshold, or regularize a phase distribution between the first local minimum point and the point with the maximum amplitude and between the point with the maximum amplitude and the second local minimum point when both a third time interval between the first local minimum point and the point with the maximum amplitude and a fourth time interval between the point with the maximum amplitude and the second local minimum point are smaller than a preset threshold.

In this embodiment, the preset threshold may be determined according to an upper limit value of a cycle range of respiration or heartbeat of the living body. For example, the preset threshold is an upper limit value T_HK is a predetermined coefficient, e.g., k is a positive number less than or equal to 2.

For example, when the detection object is a breathing frequency, the upper limit of the cycle range of breathingValue T_HIs 6 seconds, in which case the preset threshold is 6/k.

For another example, when the detection object is a heartbeat frequency, the upper limit value T of the cycle range of the heartbeat_HIt was 1.2 seconds. In this case, the preset threshold is 1.2/k.

Hereinafter, the procedure of the homogenization process will be described by taking the case where the local extreme point is the local maximum point as an example.

All local maximum points of the phase distribution subjected to phase unwrapping are denoted by (M)₁,M₂,…,M_n) Corresponding times are respectivelyWherein M is_iIs a time windowThe maximum point in the range corresponding to the time beingTo (M)₁,M₂,…,M_n) Each pair of two adjacent local maximum points (M)_i,M_i+1) The FFT signal in between is subjected to the equalization processing of the amplitude.

Fig. 6 is a schematic diagram of a method for homogenizing the amplitude of a phase distribution between two adjacent local maximum points according to embodiment 1 of the present invention. As shown in fig. 6, the method includes:

step 601: determining two adjacent local maximum points (M)_i,M_i+1) Minimum value point L of phase distribution therebetween_iThe minimum point corresponds to a time of

Step 602: judgment M_iAnd L_iTime interval betweenL_iAnd M_i+1Time betweenPartitionWhether all are less than the preset threshold value T_HK is; when the judgment result is yes, entering step 603, and when the judgment result is no, ending the process;

step 603: will M_iAnd L_i、L_iAnd M_i+1The phase distribution between is normalized to (-a, a).

For example, for amplitude at M_iAnd L_iThe normalized value of x can be calculated according to the following formula (3):

x′＝2(x-L_i)/(M_i-L_i)A-A (3)

wherein x' represents the amplitude after regularization, x represents the amplitude before regularization, L_iRepresenting the magnitude of the minimum point and a representing the regularization magnitude parameter.

And (3) executing the steps 601-603 on each pair of adjacent local maximum points, thereby completing amplitude homogenization treatment on the whole phase distribution.

The above takes the local extreme point as the local maximum point as an example, and the homogenization process is described, and for the case where the local extreme point is the local minimum, the processing manner is similar to the above method, and is not described again here.

In this embodiment, since different time windows are used for detecting respiration and detecting heartbeat, the first determining unit 103 determines different local extreme points for detecting respiration and detecting heartbeat, and the uniformizing unit 104 performs uniformization processing on the different local extreme points to obtain different amplitude-uniformized phase distributions. Fig. 7 is a schematic view of a curve of the homogenized phase distribution obtained when respiration is detected in embodiment 1 of the present invention, and fig. 8 is a schematic view of a curve of the homogenized phase distribution obtained when heartbeat is detected in embodiment 1 of the present invention. As shown in fig. 7 and 8, the ordinate of the phase distribution after the homogenization treatment does not indicate a specific phase, but indicates a relative magnitude relationship, and there is no unit.

In the present embodiment, after the uniformizing unit 104 performs the uniformizing process of the amplitude value on the phase distribution between each pair of adjacent local extreme points, the second calculating unit 105 calculates the frequency of respiration or heartbeat of the living body based on the phase distribution subjected to the uniformizing process of the amplitude value.

Fig. 9 is a schematic diagram of the second calculating unit 105 according to embodiment 1 of the present invention. As shown in fig. 9, the second calculation unit 105 includes:

a filtering unit 901 for performing band-pass filtering on the phase distribution subjected to the homogenization processing of the amplitude; and

a third calculation unit 902 for calculating a frequency of breathing or heartbeat of the living being from the band-pass filtered phase distribution.

In this embodiment, the filtering unit 901 performs band-pass filtering on the phase distribution subjected to the equalization processing of the amplitude, and different band-pass frequencies can be used for detecting respiration and detecting heartbeat.

For example, for detecting breathing, the band pass frequency range at the time of band pass filtering is set to 10 times/minute to 20 times/minute; for detecting heartbeats, the band pass frequency range at the time of band pass filtering is set to 50 times/minute to 200 times/minute.

FIG. 10 is a schematic diagram of a curve obtained by band-pass filtering the homogenized phase distribution obtained in the breath detection shown in FIG. 7 according to embodiment 1 of the present invention; fig. 11 is a schematic diagram of a curve obtained by band-pass filtering the homogenized phase distribution obtained in detecting the heartbeat shown in fig. 8 according to embodiment 1 of the present invention. As shown in fig. 10 and 11, after the homogenization process and the band-pass filtering, the signal fluctuation caused only by the respiration or the heartbeat is obtained, so that the frequency of the respiration or the heartbeat can be accurately calculated. In addition, as shown in fig. 10 and 11, similarly to the signals shown in fig. 7 and 8, the ordinate does not indicate a specific phase any more, but indicates a relative magnitude relationship, which has no unit.

In the present embodiment, the third calculation unit 902 calculates the frequency of breathing or heartbeat of the living body from the band-pass filtered phase distribution. The following is an exemplary description of the calculation method thereof.

Fig. 12 is a schematic diagram of the third calculating unit 902 according to embodiment 1 of the present invention. As shown in fig. 12, the third calculation unit 902 includes:

a counting unit 1201, configured to count the number of local extremum points in the bandpass filtered phase distribution within a second preset time range; and

a fourth calculating unit 1202 for calculating the frequency of breathing or heartbeat of the living being according to the counted number of extreme points.

In this embodiment, the counting unit 1201 counts the number of local extreme points in the band-pass filtered phase distribution within the second preset time range. The second preset time range may be determined according to actual conditions, for example, the second preset time range is an area where extreme points are concentrated, or the second preset time range may be the entire first preset time range. The local extreme point may be a local maximum or a local minimum.

For example, the number of local maxima in fig. 10 is counted for detecting breaths, and the number of local maxima in fig. 11 is counted for detecting heartbeats.

The fourth calculation unit 1202 calculates the frequency of breathing or heartbeat of the living body from the counted number of local extreme points.

For example, the frequency of breathing or heartbeat may be calculated according to the following equation (4):

F＝N/T (4)

where F denotes the frequency of breathing or heartbeat, N denotes the number of local extreme points, and T denotes the time for which the signal for counting the local extreme points lasts.

As can be seen from the above-described embodiments, by determining the local extreme points of the phase distribution and performing the amplitude equalization processing on the signal between each pair of adjacent local extreme points, it is possible to enhance and equalize the signal fluctuation caused by respiration or heartbeat as the detection target, thereby eliminating the influence of noise caused by factors such as movement or micromotion of the living body, radar signals reflected by other objects, and respiratory harmonics, and obtaining high detection accuracy.

Example 2

An embodiment of the present invention further provides an electronic device, and fig. 13 is a schematic diagram of the electronic device in embodiment 2 of the present invention. As shown in fig. 13, the electronic device 1300 includes a vital sign detection apparatus 1301, wherein the structure and function of the vital sign detection apparatus 1301 are the same as those described in embodiment 1, and are not described herein again.

Fig. 14 is a schematic block diagram of a system configuration of an electronic apparatus according to embodiment 2 of the present invention. As shown in fig. 14, the electronic device 1400 may include a central processor 1401 and a memory 1402; the memory 1402 is coupled to the central processor 1401. The figure is exemplary; other types of structures may also be used in addition to or in place of the structure to implement telecommunications or other functions.

As shown in fig. 14, the electronic device 1400 may further include: an input unit 1403, a display 1404, and a power source 1405.

For example, the functions of the vital sign detection apparatus described in embodiment 1 may be integrated into the central processor 1401. The central processor 1401 may be configured to: calculating the phase distribution of the distance Fast Fourier Transform (FFT) signal of the position of the living body along with the time change according to the reflected signal of the microwave radar in the first preset time range; performing phase unwrapping on the phase distribution; determining all local extreme points of the phase distribution subjected to phase unwrapping according to a preset time window, wherein the time window is determined according to the periodic range of respiration or heartbeat of the living body; carrying out amplitude homogenization treatment on the phase distribution between each pair of adjacent local extreme points; and calculating the frequency of respiration or heartbeat of the living body according to the phase distribution subjected to the amplitude homogenization treatment.

For example, according to a preset time window, all local extreme points of the phase distribution subjected to phase unwrapping are determined, including: the time windows are shifted on the time axis of the phase-unwrapped phase profile to determine whether there is a local extreme point in each time window, thereby obtaining all local extreme points throughout the phase-unwrapped phase profile.

For example, the width of the time window is an integral multiple of the lower limit value of the cycle range of the respiration or heartbeat of the living body.

For example, the local extreme point is a local maximum point or a local minimum point, and the process of homogenizing the amplitude of the phase distribution between each pair of adjacent local extreme points includes: determining a point with the minimum amplitude between the adjacent first local maximum point and the second local maximum point, or determining a point with the maximum amplitude between the adjacent first local minimum point and the second local minimum point; and when a first time interval between the first local maximum point and the point with the minimum amplitude and a second time interval between the point with the minimum amplitude and the second local maximum point are both smaller than a preset threshold value, regularizing phase distributions between the first local maximum point and the point with the minimum amplitude and between the point with the minimum amplitude and the second local maximum point, or regularizing phase distributions between the first local minimum point and the point with the maximum amplitude and between the point with the second local minimum point when a third time interval between the first local minimum point and the point with the maximum amplitude and a fourth time interval between the point with the maximum amplitude and the second local minimum point are both smaller than the preset threshold value.

For example, the preset threshold is determined according to an upper limit value of a cycle range of respiration or heartbeat of the living body.

For example, calculating the frequency of respiration or heartbeat of the living body from the phase distribution subjected to the equalization processing of the amplitude includes: performing band-pass filtering on the phase distribution subjected to the amplitude homogenization treatment; and calculating the frequency of the respiration or heartbeat of the living body according to the phase distribution subjected to the band-pass filtering.

For example, calculating the frequency of the respiration or heartbeat of the living being from the band-pass filtered phase profile includes: counting the number of local extreme points in the phase distribution subjected to band-pass filtering in a second preset time range; and calculating the frequency of the respiration or heartbeat of the living body according to the counted number of the extreme points.

For another example, the vital sign detection apparatus described in embodiment 1 may be configured separately from the central processor 1401, and for example, the vital sign detection apparatus may be a chip connected to the central processor 1401, and the function of the vital sign detection apparatus may be realized by the control of the central processor 1401.

It is not necessary that the electronic device 1400 in this embodiment include all of the components shown in fig. 14.

As shown in fig. 14, a central processor 1401, also sometimes referred to as a controller or operational control, may include a microprocessor or other processor device and/or logic device, the central processor 1401 receiving input and controlling the operation of the various components of the electronic device 1400.

The memory 1402, for example, may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, or other suitable device. And the central processor 1401 can execute the program stored in the memory 1402 to realize information storage or processing, or the like. The functions of other parts are similar to the prior art and are not described in detail here. The various components of the electronic device 1400 may be implemented in dedicated hardware, firmware, software, or combinations thereof, without departing from the scope of the invention.

As can be seen from the above-described embodiments, by determining local extreme points of the time-varying phase distribution of the range fast fourier transform signal and performing amplitude equalization processing on the signal between each pair of adjacent local extreme points, it is possible to enhance and equalize signal fluctuations caused by respiration or heartbeat as a detection target, thereby eliminating the influence of noise caused by factors such as movement or micromotion of a living body, radar signals reflected by other objects, and respiratory harmonics, and obtaining high detection accuracy.

Example 3

The embodiment of the invention also provides a vital sign detection system, which comprises a microwave radar and a vital sign detection device, wherein the structure and the function of the vital sign detection device are the same as those described in the embodiment 1, and detailed contents are not repeated.

Fig. 15 is a schematic diagram of a vital sign detection system according to embodiment 3 of the present invention, and as shown in fig. 15, a vital sign detection system 1500 includes:

a microwave radar 1510 including a signal transmitting unit 1511 and a signal receiving unit 1512, the signal transmitting unit 1511 transmitting a microwave signal to a space where a living body is located, and the signal receiving unit 1512 receiving a reflected signal; and

and a vital sign detection device 1520 for detecting a vital sign based on the reflected signal.

For example, microwave radar 1510 is a microwave radar having a three-dimensional antenna array. The specific structure and function of the signal transmitting part 1511 and the signal receiving part 1512 of the microwave radar 1510 can refer to the related art.

In this embodiment, the structure and function of the vital sign detection device 1520 are the same as those described in embodiment 1, and detailed description thereof will not be repeated.

As can be seen from the above-described embodiments, by determining local extreme points of the time-varying phase distribution of the range fast fourier transform signal and performing amplitude equalization processing on the signal between each pair of adjacent local extreme points, it is possible to enhance and equalize signal fluctuations caused by respiration or heartbeat as a detection target, thereby eliminating the influence of noise caused by factors such as movement or micromotion of a living body, radar signals reflected by other objects, and respiratory harmonics, and obtaining high detection accuracy.

Example 4

The embodiment of the invention also provides a method for detecting the vital signs, which corresponds to the device for detecting the vital signs in the embodiment 1. Fig. 16 is a schematic diagram of a vital sign detection method according to embodiment 4 of the present invention. As shown in fig. 16, the method includes:

step 1601: calculating the phase distribution of the distance Fast Fourier Transform (FFT) signal of the position of the living body along with the time change according to the reflected signal of the microwave radar in the first preset time range;

step 1602: performing phase unwrapping on the phase distribution; and

step 1603: determining all local extreme points of the phase distribution subjected to phase unwrapping according to a preset time window, wherein the time window is determined according to the periodic range of respiration or heartbeat of the living body;

step 1604: carrying out amplitude homogenization treatment on the phase distribution between each pair of adjacent local extreme points; and

step 1605: and calculating the frequency of the respiration or heartbeat of the living body according to the phase distribution subjected to the amplitude homogenization treatment.

In this embodiment, the specific implementation method in each step is the same as that described in embodiment 1, and is not described herein again.

As can be seen from the above-described embodiments, by determining local extreme points of the time-varying phase distribution of the range fast fourier transform signal and performing amplitude equalization processing on the signal between each pair of adjacent local extreme points, it is possible to enhance and equalize signal fluctuations caused by respiration or heartbeat as a detection target, thereby eliminating the influence of noise caused by factors such as movement or micromotion of a living body, radar signals reflected by other objects, and respiratory harmonics, and obtaining high detection accuracy.

An embodiment of the present invention further provides a computer-readable program, where when the program is executed in a device for detecting a vital sign or an electronic device, the program causes a computer to execute the method for detecting a vital sign according to embodiment 4 in the device for detecting a vital sign or the electronic device.

The embodiment of the present invention further provides a storage medium storing a computer readable program, where the computer readable program enables a computer to execute the method for detecting a vital sign described in embodiment 4 in a vital sign detection apparatus or an electronic device.

The method for detecting vital signs performed in the apparatus or electronic device for detecting vital signs described in connection with the embodiments of the present invention may be directly embodied as hardware, a software module executed by a processor, or a combination of the two. For example, one or more of the functional block diagrams and/or one or more combinations of the functional block diagrams illustrated in fig. 1 may correspond to individual software modules of a computer program flow or may correspond to individual hardware modules. These software modules may correspond to the steps shown in fig. 16, respectively. These hardware modules may be implemented, for example, by solidifying these software modules using a Field Programmable Gate Array (FPGA).

A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. A storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium; or the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The software module may be stored in the memory of the mobile terminal or in a memory card that is insertable into the mobile terminal. For example, if the apparatus (e.g., mobile terminal) employs a relatively large capacity MEGA-SIM card or a large capacity flash memory device, the software module may be stored in the MEGA-SIM card or the large capacity flash memory device.

One or more of the functional block diagrams and/or one or more combinations of the functional block diagrams described with respect to fig. 1 may be implemented as a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein. One or more of the functional block diagrams and/or one or more combinations of the functional block diagrams described with respect to fig. 1 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP communication, or any other such configuration.

While the invention has been described with reference to specific embodiments, it will be apparent to those skilled in the art that these descriptions are illustrative and not intended to limit the scope of the invention. Various modifications and alterations of this invention will become apparent to those skilled in the art based upon the spirit and principles of this invention, and such modifications and alterations are also within the scope of this invention.

The embodiment of the invention also discloses the following attached notes:

1. a method of vital sign detection, the method comprising:

calculating the phase distribution of the distance Fast Fourier Transform (FFT) signal of the position of the living body along with the time change according to the reflected signal of the microwave radar in the first preset time range;

performing phase unwrapping on the phase distribution;

determining all local extreme points of the phase distribution subjected to phase unwrapping according to a preset time window, wherein the time window is determined according to the periodic range of respiration or heartbeat of the living body;

carrying out amplitude homogenization treatment on the phase distribution between each pair of adjacent local extreme points; and

and calculating the frequency of the respiration or heartbeat of the living body according to the phase distribution subjected to the amplitude homogenization treatment.

2. The method according to supplementary note 1, wherein determining all local extreme points of the phase distribution subjected to the phase unwrapping according to a preset time window includes:

shifting the time windows on the time axis of the phase unwrapped phase profile, and determining whether each time window has a local extreme point, thereby obtaining all local extreme points on the entire phase unwrapped phase profile.

3. The method according to supplementary note 1, wherein,

the width of the time window is an integral multiple of a lower limit value of a periodic range of respiration or heartbeat of the living body.

4. The method according to supplementary note 1, wherein the local extreme point is a local maximum point or a local minimum point,

the method for homogenizing the amplitude of the phase distribution between each pair of adjacent local extreme points comprises the following steps:

determining a point with the minimum amplitude between the adjacent first local maximum point and the second local maximum point, or determining a point with the maximum amplitude between the adjacent first local minimum point and the second local minimum point; and

when both a first time interval between the first local maximum point and the point with the minimum amplitude and a second time interval between the point with the minimum amplitude and the second local maximum point are smaller than a preset threshold value, regularizing phase distributions between the first local maximum point and the point with the minimum amplitude and between the point with the minimum amplitude and the second local maximum point, or regularizing phase distributions between the first local minimum point and the point with the maximum amplitude and between the point with the maximum amplitude and the second local minimum point when both a third time interval between the first local minimum point and the point with the maximum amplitude and a fourth time interval between the point with the maximum amplitude and the second local minimum point are smaller than the preset threshold value.

5. The method according to supplementary note 4, wherein,

the preset threshold is determined according to an upper limit value of a cycle range of respiration or heartbeat of the living body.

6. The method according to supplementary note 1, wherein the calculating of the frequency of respiration or heartbeat of the living body from the amplitude-homogenized phase distribution includes:

performing band-pass filtering on the phase distribution subjected to the amplitude homogenization treatment; and

and calculating the frequency of the respiration or heartbeat of the living body according to the phase distribution subjected to the band-pass filtering.

7. The method according to supplementary note 6, wherein calculating the frequency of respiration or heartbeat of the living body from the band-pass filtered phase distribution includes:

counting the number of local extreme points in the phase distribution subjected to band-pass filtering in a second preset time range; and

and calculating the breathing or heartbeat frequency of the living body according to the counted number of the extreme points.