CN112965060A

CN112965060A - Detection method and device for vital sign parameters and method for detecting physical sign points

Info

Publication number: CN112965060A
Application number: CN202110191890.9A
Authority: CN
Inventors: 林焰
Original assignee: Calterah Semiconductor Technology Shanghai Co Ltd
Current assignee: Calterah Semiconductor Technology Shanghai Co Ltd
Priority date: 2021-02-19
Filing date: 2021-02-19
Publication date: 2021-06-15

Abstract

The embodiment of the invention discloses a method and a device for detecting vital sign parameters and a method for detecting sign points. Wherein, the method comprises the following steps: determining echo intermediate frequency signals of the echo signal frames according to the emission signals of at least two groups of emission signal frames and the echo signals of at least two groups of echo signal frames; determining a target one-dimensional range profile between any group of echo signal frames and at least one object to be measured based on fast Fourier transform according to the echo intermediate frequency signals; filtering actual phases of sampling points in the target one-dimensional range profile according to a preset phase extraction method to obtain a first matrix representing target phases of the sampling points; determining a power spectrum ratio of the power of each element in the first matrix to the total power of the row of the element according to a preset power spectrum determination algorithm to obtain a second matrix; and determining target sign points in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determination rule so as to obtain vital characteristic parameters of the target sign points.

Description

Detection method and device for vital sign parameters and method for detecting physical sign points

Technical Field

The embodiment of the invention relates to a target detection technology, in particular to a method and a device for detecting vital sign parameters and a method for detecting sign points.

Background

When a sensor (such as a radar) is used for detecting parameters with fine periodic motion, for example, vital sign parameters such as pulse, respiration and heartbeat of a human body sign point are detected, the accuracy of the selection of the sign point directly determines the accuracy of the detection of the vital sign parameters. If the sign points are selected to be deviated, signals such as respiration and heartbeat are extracted subsequently based on wrong sign points, and therefore the vital sign parameters are determined wrongly.

When the existing sensor determines the vital sign parameters, a maximum method is generally adopted to determine the vital sign points, that is, the maximum amplitude of a one-dimensional range profile of an echo signal is searched, and the maximum amplitude point in the one-dimensional range profile is used as the human body vital sign point. However, when an interfering object exists in the scene, especially when a plurality of interfering objects exist, the interfering objects may cause a positioning error of the vital sign points, thereby affecting the determination efficiency and accuracy of the vital sign parameters.

Disclosure of Invention

The embodiment of the invention provides a method and a device for detecting vital sign parameters and a method for detecting sign points, which are used for improving the detection precision and efficiency of the vital sign parameters.

In a first aspect, an embodiment of the present invention provides a method for detecting vital sign parameters, where the method includes:

determining echo intermediate frequency signals of the echo signal frames according to the emission signals of at least two groups of emission signal frames and the echo signals of at least two groups of echo signal frames;

determining a target one-dimensional range profile between any group of echo signal frames and at least one object to be measured based on fast Fourier transform according to echo intermediate frequency signals of the echo signal frames;

filtering the actual phase of the sampling point in the target one-dimensional range profile according to a preset phase extraction method to obtain a first matrix for representing the target phase of the sampling point;

determining a power spectrum ratio of the power of each element in the first matrix to the total power of the row of the element according to a preset power spectrum determination algorithm to obtain a second matrix;

and determining target sign points in sampling points according to the power spectrum ratio in the second matrix and a preset sign point determination rule so as to obtain vital characteristic parameters of the target sign points.

In a second aspect, an embodiment of the present invention further provides an apparatus for detecting a vital sign parameter, where the apparatus includes:

the intermediate frequency signal determining module is used for determining echo intermediate frequency signals of the echo signal frames according to the transmitting signals of the at least two groups of transmitting signal frames and the echo signals of the at least two groups of echo signal frames;

the target range profile determining module is used for determining a target one-dimensional range profile between any group of echo signal frames and at least one object to be measured based on fast Fourier transform according to echo intermediate frequency signals of the echo signal frames;

the first matrix determining module is used for filtering the actual phase of the sampling point in the target one-dimensional range profile according to a preset phase extraction method to obtain a first matrix for representing the target phase of the sampling point;

the second matrix determining module is used for determining the power spectrum ratio of the power of each element in the first matrix to the total power of the row of the element according to a preset power spectrum determining algorithm to obtain a second matrix;

and the target point determining module is used for determining a target sign point in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determining rule so as to obtain the vital characteristic parameters of the target sign point.

In a third aspect, an embodiment of the present invention further provides a method for detecting a sign point, which may include:

acquiring an echo signal, and performing signal processing on the echo signal to obtain one-dimensional range profile data; the echo signals comprise M frame signals, and each frame signal comprises N unit signals; the one-dimensional range profile data comprises M groups of data, and each group of data in the M groups of data comprises N one-dimensional range profiles;

respectively performing coherent superposition on each group of data in the M groups of data to obtain M coherent superposition one-dimensional range profiles corresponding to zero Doppler;

respectively extracting the phase of each coherent superposition one-dimensional range profile in the M coherent superposition one-dimensional range profiles on each range cell, and unwrapping each range cell on a slow time dimension to obtain an M x K phase range matrix S1;

acquiring a power spectrum ratio of each element in a distance dimension based on the matrix S1 to obtain a distance power spectrum ratio matrix S2 of M x K; and

in the matrix S2, at least one element, which has the largest power spectrum ratio in the power spectrum ratio dimension and the entropy value satisfying the preset condition, is taken as the sign point;

wherein M, N, K are all positive integers greater than or equal to 2.

In this embodiment, by using parameters such as the power spectrum ratio and the entropy to locate the sign points, compared with the conventional maximum value method, the location of the sign points is more accurate, and meanwhile, the influence of an interfering object can be effectively reduced or even avoided, so that the method is more suitable for complex scenes and has stronger robustness.

Optionally, the method for detecting the physical sign points in the embodiment of the present application may be applied to an FMCW (Frequency Modulated Continuous Wave Radar) sensor; the signal processing of the echo signal to obtain one-dimensional range profile data includes:

performing frequency mixing, sampling and two-dimensional fast Fourier transform on the echo information to obtain the one-dimensional range profile data of M groups of N echo unit signals;

wherein the unit signal is a chirp signal (chirp).

Optionally, the unwrapping each range cell in the slow time dimension to obtain the phase-distance matrix of M × K S1 includes:

after unwrapping each range bin in the slow time dimension, high pass filtering is performed to obtain the M x K phase range matrix S1.

Optionally, the matrix S1 has a row phase dimension and a column distance dimension; the obtaining of the power spectrum ratio of each element in the distance dimension based on the matrix S1 to obtain a distance power spectrum ratio matrix S2 of M × K includes:

performing fast fourier transform on each column of the matrix S1 and obtaining a power spectrum; and

the ratio of the power of each element in each column of the matrix S1 to the total power of the column is calculated to obtain the matrix S2.

Optionally, the row of the matrix S2 is a distance dimension, and the column is a power spectrum ratio dimension; in the matrix S2, taking at least one element, as the sign point, of which the power spectrum ratio is maximum in the power spectrum ratio dimension and the entropy value satisfies the preset condition, the method includes:

acquiring an element with the power spectrum ratio of each column in the matrix S2 as a maximum value as a sign point to be confirmed;

obtaining an entropy value of each column in the matrix S2; and

and taking the sign point to be confirmed with the entropy value meeting the preset condition as the sign point.

Optionally, the preset condition is that the rows are arranged in the rearmost predetermined number in sequence from large to small according to the entropy value;

wherein the predetermined number is greater than or equal to 1, for example, the predetermined number is 2, 3, 5, or 7.

In a fourth aspect, an embodiment of the present application further provides a method for tracking a vital sign point, which may include:

the method according to any embodiment of the application is repeated in a circulating manner to track the sign points in real time, and therefore the change of the positions of the sign points can be tracked in real time.

In a fifth aspect, an embodiment of the present invention further provides a method for acquiring a respiratory rate, which may include:

obtaining the sign points by using the method according to any embodiment of the application;

obtaining a slow time phase power spectrum V1 at the sign point based on the sign point in the matrix S2; and

and acquiring a maximum power value in a preset breathing frequency band in the slow time phase power spectrum V1 to obtain the breathing rate.

Optionally, the preset breathing frequency range is 0.15-0.5 Hz.

Optionally, the obtaining a maximum power value in a preset breathing frequency band in the slow time phase power spectrum V1 to obtain the breathing rate includes:

and acquiring a maximum power value in a preset breathing frequency band in the slow time phase power spectrum V1, and multiplying a frequency point corresponding to the maximum power value by 60 to obtain the breathing rate.

In a sixth aspect, an embodiment of the present invention further provides a method for acquiring a heart rate, where the method includes:

obtaining a slow time phase power spectrum V1 at the sign point based on the sign point in the matrix S2;

extracting and accumulating elements in a preset range of each sign point in the matrix S2 to obtain a slow time phase power spectrum V2;

accumulating values obtained in the slow time phase power spectrum V2 in a preset heart rate frequency band to obtain a vector spectrum V3, namely accumulating values obtained based on the current M frames (or the current M groups of signals) and values obtained by all previous M frames to obtain a vector spectrum V3; and

and acquiring the frequency point corresponding to the maximum value in the vector spectrum V3 to obtain the heart rate.

In this embodiment, by using a space-time joint calculation mode, by performing joint analysis on distance units around confirmed sign points and summarizing the confirmed sign point data in combination with historical sign point data, the problem of deviation between the sign point position and the heartbeat echo point can be effectively avoided, and stable detection performance can be maintained under the condition that the heartbeat echo signal-to-noise ratio is unstable. In addition, the detected heart rate will be more and more stable as the detection time is accumulated.

Optionally, the preset heart rate frequency band is 0.9-2 Hz.

Optionally, the obtaining a frequency point corresponding to a maximum value in the vector spectrum V3 to obtain the heart rate includes:

and multiplying the frequency point corresponding to the maximum value in the vector spectrum V3 by 60 to obtain the heart rate.

Optionally, the heart rate frequency band includes a heartbeat frequency band and/or a pulsation frequency band.

Optionally, when the heart rate frequency band includes a heartbeat frequency band and a pulsation frequency band, the method further includes:

and outputting corresponding warning information by judging the size relationship between the heart rate obtained by the heartbeat frequency band and the heart rate obtained by the pulse frequency band.

It should be noted that, because the heartbeat rate is greater than or equal to the pulsation rate, when the heartbeat rate is detected to be less than the pulsation rate or the value less than the pulsation rate is outside the preset range, it can be determined that the current detection system has a fault, so that a prompt message of the system fault can be output. In addition, by combining the medical principle, when the heartbeat rate is detected to be greater than the pulse rate or greater than a preset range, the information of abnormal heart rate can be output while the heartbeat rate and the pulse rate value are output, so as to assist in diagnosing the ecological characteristic parameters; if the heartbeat rate is detected to be equal to the pulse rate or within a preset range, the heartbeat rate and the pulse rate value can be output, and meanwhile, green marks and other marks can be output to indicate that the vital signs of the target are abnormal.

In a seventh aspect, an embodiment of the present invention further provides a detection apparatus, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor executes the computer program to implement the method according to any embodiment of the present invention.

In an eighth aspect, embodiments of the present invention further provide a storage medium containing computer-executable instructions, which when executed by a computer processor, are configured to perform the method according to any of the embodiments of the present invention.

According to the embodiment of the invention, echo signals are processed, each group of echo signal frames corresponds to one target one-dimensional range profile, and the phases of sampling points are filtered according to the target one-dimensional range profiles to generate a first matrix. Through filtering the phase place, can reduce the influence of a plurality of interferents to target sign point, first matrix is used for expressing the phase value of each sampling point after the filtering. According to the first matrix, a second matrix representing the power spectrum ratio is generated, and the target sign point is selected from the second matrix according to the power spectrum ratio, so that the problem that the target sign point is inaccurate due to the fact that the target sign point is determined through the one-dimensional range profile is solved. In the prior art, the target sign point is directly determined after the one-dimensional range profile is obtained, the first matrix and the second matrix are generated, so that the interference of a plurality of objects in the environment is avoided, the determination accuracy of the target sign point is improved, other vital sign parameters are obtained according to the target sign point, and the determination efficiency and the determination accuracy of the vital sign parameters are improved.

Drawings

Fig. 1 is a schematic flowchart of a method for detecting vital sign parameters according to a first embodiment of the present invention;

fig. 2 is a schematic flow chart of a method for detecting vital sign parameters according to a second embodiment of the present invention;

fig. 3 is a block diagram of a detecting apparatus for vital sign parameters according to a third embodiment of the present invention;

fig. 4 is a schematic structural diagram of a detecting apparatus in the fourth embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Example one

Fig. 1 is a schematic flow chart of a method for detecting vital sign parameters according to an embodiment of the present invention, which is applicable to a case of determining vital sign parameters of human body sign points, and the method can be executed by a device for detecting vital sign parameters. As shown in fig. 1, the method specifically includes the following steps:

step 110, determining an echo intermediate frequency signal of the echo signal frame according to the emission signals of the at least two groups of emission signal frames and the echo signals of the at least two groups of echo signal frames.

The radar detector transmits signals to the surrounding environment to determine target sign points of the human body. The transmitted signals may be chirped continuous wave signals, at least two sets of chirped continuous wave signals being transmitted. Each set of the chirp continuous wave signals is a set of transmission signal frames, each set of the transmission signal frames may include at least two chirp continuous waves, the chirp continuous waves are used as transmission signals in the transmission signal frames, and the chirp continuous waves may be chrip (chirp) signals. For example, the radar transmits M sets of transmission signal frames, with N transmission signals in each set of transmission signal frames. After the radar transmits the transmission signal frames, the radar can receive echo signal frames reflected by objects in the environment, and each group of echo signal frames can correspond to one group of transmission signal frames. The objects in the environment may be static objects such as human bodies or non-human bodies, for example, non-human bodies may be walls, cars, trees, and the like. If the radar transmits three groups of transmitting signal frames, three groups of echo signal frames can be received, and at least two echo signals exist in each group of echo signal frames. The echo signals correspond to the transmitting signals in the corresponding transmitting signal frames one by one, and if five transmitting signals exist in a group of transmitting signal frames, five echo signals exist in the corresponding echo signal frames. According to the transmitting signal and the corresponding echo signal, the echo intermediate frequency signal of the echo signal can be determined, for example, the echo signal can be subjected to difference frequency processing according to the transmitting signal to obtain the echo intermediate frequency signal.

In this embodiment, optionally, determining the echo intermediate frequency signal of the echo signal frame according to the transmit signal of the at least two sets of transmit signal frames and the echo signal of the at least two sets of echo signal frames includes: receiving at least two groups of echo signal frames associated with a transmitted signal frame; the number of the groups of the transmitting signal frames is the same as that of the echo signal frames, at least two echo signals exist in one group of echo signal frames, and the number of the transmitting signals in one group of the transmitting signal frames is the same as that of the echo signals in one group of the echo signal frames; according to the transmitting signal of the transmitting signal frame, carrying out difference frequency processing on the echo signal in the echo signal frame associated with the transmitting signal frame to obtain an echo intermediate frequency signal; wherein, the number of echo intermediate frequency signals is the same as the number of echo signals.

Specifically, the number of groups of transmitted signal frames transmitted by the radar is the same as the number of groups of received echo signal frames, the number of transmitted signals in the transmitted signal frames is also the same as the number of echo signals in the echo signal frames, the radar transmits at least two groups of transmitted signal frames, and each group of transmitted signal frames has at least two transmitted signals. And determining an echo signal frame corresponding to each group of transmission signal frames, and performing difference frequency processing on corresponding echo signals according to the transmission signals of the transmission signal frames. For example, the echo signal may be conjugate multiplied with the transmit signal to obtain an echo intermediate frequency signal. The number of echo intermediate frequency signals corresponds to the number of echo signals, i.e. to the number of transmitted signals. If the radar transmits M groups of transmitting signal frames, and each group of transmitting signal frames has N transmitting signals, the number of echo signal frames is M, the number of echo signals of each group is N, and the number of echo intermediate frequency signals of each group is N. The beneficial effect who sets up like this lies in, according to the transmission signal, can obtain echo signal and echo intermediate frequency signal, is convenient for obtain the one-dimensional range profile of target according to echo intermediate frequency signal, improves the definite accuracy of the one-dimensional range profile of target, and then improves the definite accuracy of vital sign parameter.

And step 120, determining a target one-dimensional range profile between any group of echo signal frames and at least one object to be measured based on fast Fourier transform according to the echo intermediate frequency signals of the echo signal frames.

Each echo intermediate frequency signal of each group of echo signal frames is acquired, and Fast Fourier Transform (FFT) is performed on each echo intermediate frequency signal. One-dimensional range profiles can be obtained according to the FFT, the one-dimensional range profiles in this embodiment can be low-resolution range profiles, and the number of the one-dimensional range profiles is the same as the number of the echo intermediate frequency signals. And combining the multiple one-dimensional range profiles of each group according to a preset one-dimensional range profile addition algorithm to obtain a target one-dimensional range profile. Each group of echo signal frames corresponds to a target one-dimensional range profile. After the echo intermediate frequency signal is obtained, sampling can be performed on the echo intermediate frequency signal according to a preset sampling rate, at least two sampling points can be obtained on each echo intermediate frequency signal, a target sign point can be selected conveniently from the sampling points, and the determination efficiency of the target sign point is improved.

In this embodiment, optionally, determining a one-dimensional range profile of a target between any group of echo signal frames and at least one object to be measured based on fast fourier transform according to the echo intermediate frequency signals of the echo signal frames includes: performing fast Fourier transform on any echo intermediate frequency signal in at least two groups of echo signal frames to obtain an initial one-dimensional range profile of the echo intermediate frequency signal; and carrying out coherent superposition processing on at least two initial one-dimensional range profiles in each group of echo signal frames to obtain a target one-dimensional range profile corresponding to each group of echo signal frames.

Specifically, fast fourier transform is performed on each echo intermediate frequency signal to obtain an initial one-dimensional range profile. The number of the initial one-dimensional range profiles is consistent with the number of the echo intermediate frequency signals, namely, each group of echo signal frames has a plurality of initial one-dimensional range profiles. The multiple initial one-dimensional range images of each group of echo signal frames are subjected to superposition processing, for example, coherent superposition processing may be performed. And superposing the plurality of initial one-dimensional range profiles of each group into a target one-dimensional range profile, namely, each group of echo signal frames corresponds to a target one-dimensional range profile, and the number of the target one-dimensional range profiles is the same as that of the echo signal frames. The one-dimensional range profile of the target may correspond to a zero doppler channel in the radar doppler processing. The method has the advantages that the multiple initial one-dimensional distance images of each group are combined, so that the phase of each sampling point can be determined according to the only one target one-dimensional distance image of each group of echo signal frames, the problem of inaccurate phase extraction caused by the multiple initial one-dimensional distance images is avoided, and the determination precision of the vital sign parameters is improved.

After the target one-bit range profile is obtained, the amplitude of the target one-dimensional range profile of the echo intermediate-frequency signal can be searched according to a maximum method of a millimeter wave respiration heartbeat detection radar, sampling points with the amplitude smaller than a preset qualified threshold value in the target one-dimensional range profile are eliminated, the determining range of target sign points is reduced, and the determining efficiency and accuracy of the target sign points are improved.

And step 130, filtering the actual phase of the sampling point in the target one-dimensional range profile according to a preset phase extraction method to obtain a first matrix for representing the target phase of the sampling point.

Therefore, based on a preset phase extraction method, the actual phase of each sampling point can be determined from the target one-dimensional range profile, the actual phase is the real phase data of each sampling point, and the range of the actual phase can be from minus infinity to plus infinity. The preset phase extraction method may be to extract the current phase of each sampling point from the target one-dimensional range profile. The current phase is a phase value derived from the target one-bit range profile and is not real phase data. And then, performing reverse thrust on the current phase according to a preset calculation formula to obtain the actual phase of the sampling point. Since there may be an interfering object in the environment, for example, a wall or a large tree, in order to improve the determination accuracy of the target vital sign point, the phase of the interfering object that is not a human body may be filtered, and in an ideal case, the phase of the filtered interfering object is 0, but since there may be noise in the echo signal, the phase value after filtering is greater than 0. And generating a first matrix according to the phase value of each filtered sampling point, wherein the first matrix represents the phase value of each sampling point in each group of echo signal frames. For example, if there are M groups of echo signal frames and K sampling points, the first matrix is an M × K matrix.

In this embodiment, optionally, filtering the actual phase of the sampling point in the one-dimensional range profile of the target according to a preset phase extraction method to obtain a first matrix for representing the target phase of the sampling point, where the method includes: extracting the current phase of the sampling point according to the one-dimensional range profile of the target; unwrapping the current phase of the sampling point in the slow time dimension to obtain the actual phase of the sampling point; carrying out high-pass filtering on the actual phase of the sampling point, and filtering low-frequency components in the actual phase to obtain a target phase of the sampling point; generating a first matrix according to the target phase of the sampling point; the number of rows of the first matrix is the same as the number of groups of echo signal frames, and the number of columns of the first matrix is the same as the number of sampling points.

Specifically, the current phase of each sampling point is determined according to the one-dimensional range profile of the target, the current phase is not the real phase data of the sampling point, and the numerical range of the current phase is-pi to pi. In order to obtain the real phase data of the sampling point, the current phase may be reversely deduced, and the current phase of the sampling point is unwrapped in the slow time dimension, for example, the current phase may be subjected to operations such as arc tangent, and real phase data from negative infinity to positive infinity, that is, the actual phase, is reversely produced. After the actual phase is obtained, high-pass filtering is carried out on the actual phase, low-frequency components in the actual phase are filtered, and the influence of an interference object is reduced. And taking the phase of each filtered sampling point as a target phase, and generating a first matrix according to the target phase. The elements in the first matrix are target phase values of all sampling points in respective echo signal frames, the number of rows of the first matrix is the same as the number of groups of the echo signal frames, and the number of columns of the first matrix is the same as the number of the sampling points. The method has the advantages that real phase data can be obtained by unwrapping the current phase, and the phase determination precision is improved. Through carrying out high-pass filtering to actual phase place, reduce the influence of interference object to confirming target sign point, improve the definite accuracy of target sign point, and then improve the definite accuracy of vital sign parameter. In this embodiment, the human body and the interfering object other than the human body are in a stationary state.

Step 140, determining a power spectrum ratio of the power of each element in the first matrix to the total power of the row in which the element is located according to a preset power spectrum determination algorithm to obtain a second matrix.

And calculating each element in the first matrix according to a preset power spectrum calculation formula, and determining a power value corresponding to each element in the first matrix. The total power of each column in the first matrix is determined based on the power value of each element. And comparing the power value of each element in the first matrix with the total power of the column where the element is positioned, and taking the obtained power spectrum ratio as the element value in the second matrix, thereby obtaining the second matrix. The number of rows and columns of the second matrix is the same as the first matrix, for example, the first matrix is an M × K matrix, and the second matrix is an M × K matrix.

In this embodiment, optionally, determining a power spectrum ratio of the power of each element in the first matrix to the total power of the column in which the element is located according to a preset power spectrum determination algorithm to obtain a second matrix includes: carrying out fast Fourier transform on any column phase value in the first matrix, and obtaining a power spectrum of any column phase value in the first matrix according to a preset power spectrum calculation formula; determining the power spectrum ratio of the power of each element in any column to the total power of the column in which the element is located according to the power spectrum of the phase value of any column; generating a second matrix according to the power spectrum ratio; the number of rows of the second matrix is the same as the number of groups of echo signal frames, and the number of columns of the second matrix is the same as the number of sampling points.

Specifically, a power value of each element in the first matrix is obtained according to a preset power spectrum determination algorithm, and the value of each element in the first matrix is a phase value. The calculation of the power spectrum may be performed sequentially for each column in the first matrix in units of columns. For example, each element in the first column is first calculated to obtain a power spectrum of each phase value in the first column. The preset power spectrum algorithm may be that the phase value of any column is subjected to fast fourier transform, and then the data after fourier transform is calculated according to a preset power spectrum calculation formula to obtain the power spectrum of the phase value of any column in the first matrix. The preset power spectrum calculation formula can be a module and a square of the data after Fourier transform. After the power spectrum of the phase value of each column is obtained, the power value of each element in each column is compared with the total power of the column, and the power spectrum ratio of the power of each element to the total power of the column where the element is located is obtained. The power spectrum ratio is taken as an element of the second matrix, so that the number of rows and columns of the second matrix is the same as that of the first matrix, namely the number of rows of the second matrix is the number of groups of echo signal frames, and the number of columns of the second matrix is the number of sampling points. For example, if M is the number of groups of echo signal frames and K is the number of sampling points, the second matrix is an M × K matrix. The method has the advantages that the power spectrum matrix is obtained according to the phase value matrix, the target sign point is determined according to the power spectrum, the problem that the sign point is determined according to the distance maximum value method is solved, the determination accuracy of the target sign point is improved, and the detection accuracy of the vital sign parameter is further improved.

And 150, determining target sign points in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determination rule so as to obtain vital characteristic parameters of the target sign points.

After the second matrix is obtained, a power spectrum ratio meeting the requirement is searched from the second matrix according to a preset sign point determination rule, and a sampling point of the power spectrum ratio is used as a target sign point. After the target sign point is detected, the vital sign parameters of the target sign point are obtained, for example, the heartbeat and the respiratory rate of the target sign point are obtained, and the detection of the vital sign parameters is completed.

In this embodiment, optionally, determining the target sign point in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determination rule includes: determining the maximum value of any column of power spectrum ratio and the entropy value of any column in the second matrix according to the power spectrum ratio in the second matrix, taking the maximum value of any column of power spectrum ratio as a candidate maximum value, and taking the entropy value of any column as a candidate entropy value; selecting a target maximum value from the candidate maximum values according to a preset sign point determination rule; determining whether the candidate entropy of the column where the target maximum value is located meets a preset sign point determination rule; and if so, determining the sampling points of the column where the target maximum value is located as target sign points.

Specifically, the preset sign point determination rule may be a screening rule for power spectrum ratio values and entropy values, where the entropy value in this embodiment refers to a discrete degree of any column of power spectrum ratio values in the second matrix. Determining the maximum value of the power spectrum ratio in each column of the second matrix in sequence, taking the obtained maximum value of the power spectrum ratio in each column as a candidate maximum value, wherein the number of the candidate maximum values is the same as the number of the columns, for example, if the second matrix is an M × K matrix, K candidate maximum values can be obtained. According to the power spectrum ratio in the second matrix, the entropy value of each column in the second matrix can be obtained, and the entropy value of each column is used as a candidate entropy value, so that K candidate entropy values are obtained. The preset sign point determination rule includes a screening rule for the power spectrum ratio, for example, the screening rule for the power spectrum ratio may specify that a maximum value of the candidate maximum values is selected as a target maximum value. After the target maximum is determined, the column where the target maximum is located may be determined, resulting in an entropy value of the column where the target maximum is located. According to the sign point determination rule, whether the entropy value of the column meets the preset requirement can be determined, and if the entropy value of the column meets the preset requirement, the sampling point of the column is determined to be the target sign point. The sign point determination rule may set a value with a larger entropy value to be determined as a value meeting a preset requirement, for example, the entropy values of the second matrix are sorted from large to small, and if the entropy value of the column where the target maximum value is located is sorted in the first three, it is determined that the entropy value of the column meets the preset sign point determination rule; if the entropy value of the column where the target maximum value is arranged behind the third bit, determining that the sampling points in the column are not the target sign points, and performing sampling on the sign points again. The beneficial effects of setting up like this lie in, through twice screening to power spectrum ratio and entropy value, make the power spectrum ratio and the entropy value of target sign point all great, greatly improve the definite precision of target sign point, be convenient for to the detection of vital sign parameter, solved and adopted the maximum method of distance to confirm the target sign point, the problem of the vital sign parameter detection mistake that causes improves the detection precision of vital sign parameter.

According to the technical scheme, echo signals are processed, each group of echo signal frames corresponds to one target one-dimensional range profile, sampling point phases are filtered according to the target one-dimensional range profiles, and a first matrix is generated. Through filtering the phase place, can reduce the influence of a plurality of interferents to target sign point, first matrix is used for expressing the phase value of each sampling point after the filtering. According to the first matrix, a second matrix representing the power spectrum ratio is generated, and the target sign point is selected from the second matrix according to the power spectrum ratio, so that the problem that the target sign point is inaccurate due to the fact that the target sign point is determined through the one-dimensional range profile is solved. According to the embodiment of the invention, the first matrix and the second matrix are generated, so that the interference of a plurality of objects in the environment is avoided, the determination precision of the target sign point is improved, other vital sign parameters are obtained according to the target sign point, and the determination efficiency and the determination precision of the vital sign parameters are improved.

Example two

Fig. 2 is a schematic flow chart of a method for detecting vital sign parameters according to a second embodiment of the present invention, which is further optimized based on the above-mentioned embodiments. As shown in fig. 2, the method specifically includes the following steps:

step 210, determining an echo intermediate frequency signal of the echo signal frame according to the emission signals of the at least two groups of emission signal frames and the echo signals of the at least two groups of echo signal frames.

And step 220, determining a target one-dimensional range profile between any group of echo signal frames and at least one object to be measured based on fast Fourier transform according to the echo intermediate frequency signals of the echo signal frames.

And step 230, filtering the actual phase of the sampling point in the target one-dimensional range profile according to a preset phase extraction method to obtain a first matrix representing the target phase of the sampling point.

And 240, determining a power spectrum ratio of the power of each element in the first matrix to the total power of the row of the element according to a preset power spectrum determination algorithm to obtain a second matrix.

And step 250, determining target sign points in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determination rule so as to obtain vital characteristic parameters of the target sign points.

And step 260, extracting columns of the target sign points in the second matrix as current first columns.

After the target sign point is determined, the column of the target sign point in the second matrix is extracted, and the column is taken as the current first column. From the power values in the current first column, a target breathing rate for the target vital sign point can be determined.

In this embodiment, optionally, after extracting a column of the target sign point in the second matrix as the current first column, the method further includes: extracting a preset number of columns from the second matrix as a current second column according to a preset column extraction rule; adding the current first column and the current second column to obtain a current third column; acquiring a current heartbeat power value in a preset heartbeat frequency band in a current third row to generate a current heartbeat power spectrum row; acquiring historical heartbeat power values in a preset heartbeat frequency band in a historical third column to generate a historical heartbeat power spectrum column; accumulating elements of the current heartbeat power spectrum column and elements of the historical heartbeat power spectrum column of the corresponding row to obtain a current fourth column; and determining the target heart rate of the target sign point from the current fourth column according to a preset heart rate determination rule.

Specifically, a column extraction rule is preset to extract a preset number of columns from the second matrix, for example, two columns on the left and two columns on the right of the column where the target sign point is located may be extracted from the second matrix, that is, four columns are extracted. And taking the extracted columns as current second columns, wherein the number of the current second columns is greater than or equal to one. And adding the current first column and the current second column, namely accumulating elements of each row in the current first column and the current second column to obtain a current third column, and saving the current third column generated each time as a historical third column for next detection of the hit characteristic parameters. The number of rows of the current first column, the current second column and the current third column is equal. The heartbeat frequency range is preset, and is the heartbeat frequency of the human body under normal conditions, for example, the heartbeat frequency range can be set to be 0.9 hertz to 2 hertz. And searching at least one power value in the heartbeat frequency band according to the range of the heartbeat frequency band to be used as the current heartbeat power value. And generating a current heartbeat power spectrum column according to the current heartbeat power value, wherein the row number of the current heartbeat power spectrum column is the same as the number of the current heartbeat power value.

And acquiring a historical third column generated before the vital sign parameter is detected, wherein the historical third column is obtained by adding a historical first column and a historical second column, the historical first column is a column of the historical target vital sign point in a historical second matrix, and the generation mode of the historical second column is the same as that of the current second column at the moment. And searching the historical heartbeat power value in the heartbeat frequency band in the historical third column to obtain a historical heartbeat power spectrum column. The number of rows of the current heartbeat power spectrum column and the number of rows of the historical heartbeat power spectrum column can be inconsistent, elements in the current heartbeat power spectrum column and elements in the historical heartbeat power spectrum column are corresponded in each row from top to bottom, and the missing rows are supplemented with 0. And adding the current heartbeat power spectrum column and the historical heartbeat power spectrum column, namely accumulating the elements of the current heartbeat power spectrum column and the elements of the historical heartbeat power spectrum column of the corresponding row to obtain a current fourth column. And determining the target heart rate of the target physical sign point from the current fourth column according to a preset heart rate determination rule, wherein the preset heart rate determination rule can be that the maximum value in the current fourth column is selected. The preset heartbeat rate determination rule can also comprise a heartbeat rate calculation formula for calculating the power, and the target heartbeat rate is calculated according to the maximum numerical value in the current fourth column and the preset heartbeat rate calculation formula. The beneficial effect who sets up like this lies in, on the detection of heartbeat, jointly analyzes the row of the sampling point around the target sign point, gathers historical sign point data simultaneously, makes the heartbeat detect and corresponds with target sign point, avoids the problem that there is the deviation in sign point position and heartbeat echo point, under the unstable condition of heartbeat echo signal to clutter ratio, guarantees the accurate detection of heartbeat rate.

In this embodiment, optionally, determining the target heart rate of the target physical sign point from the current fourth column according to a preset heart rate determination rule includes: selecting a second power value meeting a preset second power determination condition from a current fourth column; and multiplying the frequency point of the second power value by a preset value to serve as the target heart rate of the target physical sign point.

Specifically, the preset heartbeat rate determination rule may include a second power determination condition and a heartbeat rate calculation formula, and the second power determination condition may be that a maximum value in the current fourth column is selected. And searching the maximum power value from the current fourth column as a second power value according to a preset second power determination condition. The heartbeat rate calculation formula is used for calculating the second power value, for example, the frequency point of the second power value may be multiplied by a preset value to obtain the target heartbeat rate of the target physical sign point. Wherein the preset value may be 60. The method has the advantages that the target heart rate is calculated according to the current fourth column, the summary analysis of the historical sign point data is realized, and the determination accuracy of the target heart rate is improved.

And step 270, determining a target respiration rate of the target sign point from the current first column according to a preset respiration rate determination rule.

A respiration rate determination rule is preset, and a power spectrum ratio satisfying the respiration rate determination rule is selected from the current first column, for example, the maximum value of the power spectrum ratio may be selected. And obtaining the target respiration rate of the target sign point according to the selected power spectrum ratio, for example, the target respiration rate can be obtained by calculation according to a preset respiration rate calculation formula.

In this embodiment, optionally, determining the target respiration rate of the target vital sign point from the current first column according to a preset respiration rate determination rule includes: acquiring a current breathing power value in a preset breathing frequency band in a current first column; selecting a first power value satisfying a preset first power determination condition from the current breathing power values; and multiplying the frequency point of the first power value by a preset value to serve as the target respiration rate of the target physical sign point.

Specifically, the respiration rate determination rule may include a respiration frequency range and a first power determination condition, where the respiration frequency range is a respiration power value in a normal condition of the human body. The predetermined breathing frequency band range, for example, may be 0.15 hz to 0.5 hz. From the current first column, at least one power value within the breathing frequency band is selected as the current breathing power value. The first power value is selected from the current breathing power values according to a preset first power determination condition, for example, the first power determination condition is that a maximum value of the current breathing power values is selected as the first power value. And multiplying the frequency point of the first power value by a preset value to obtain the target respiration rate of the target sign point, wherein the preset value can be 60 because one minute is 60 seconds. The method has the advantages that the target respiration rate is obtained through twice screening according to the respiration frequency band and the first power determination condition, the target respiration rate corresponds to the target sign point, the phenomenon that the target respiration rate is detected mistakenly due to the existence of the interference object is avoided, and the detection precision of the target respiration rate is effectively improved.

According to the embodiment of the invention, echo signals are processed, each group of echo signal frames corresponds to one target one-dimensional range profile, and the phases of sampling points are filtered according to the target one-dimensional range profiles to generate a first matrix. Through filtering the phase place, can reduce the influence of a plurality of interferents to target sign point, first matrix is used for expressing the phase value of each sampling point after the filtering. According to the first matrix, a second matrix representing the power spectrum ratio is generated, and the target sign point is selected from the second matrix according to the power spectrum ratio, so that the problem that the target sign point is inaccurate due to the fact that the target sign point is determined through the one-dimensional range profile is solved. And extracting the column of the target sign point, and acquiring the vital sign parameters of the target sign point. According to the embodiment of the invention, the first matrix and the second matrix are generated, so that the interference of a plurality of objects in the environment is avoided, and the determination precision of the target sign point is improved. According to the column where the target sign point is located, the vital sign parameters correspond to the selected sign points, the fact that the point for detecting the vital sign parameters is not the target sign point is avoided, and the determination efficiency and the determination precision of the vital sign parameters are improved.

In the following, a method for detecting a target, that is, detecting a physical sign point, by using a sensor is described in detail, taking an FMCW millimeter wave radar as an example, in combination with practical applications:

the method can firstly utilize radar to transmit chirp continuous wave signals through a transmitting antenna, wherein the signals have M groups, each group of signals consists of N chirp continuous waves (namely unit signals), namely the chirp continuous wave signals comprise M frames, and each frame comprises N chirp signals.

The echo signal of each chirp continuous wave is subjected to difference frequency processing (i.e. mixing processing), that is, the echo signal is subjected to conjugate multiplication with the transmission signal to obtain M groups of signals, and each group of signals may include N echo intermediate frequency unit signals.

On the premise of satisfying the sampling theorem, each echo intermediate frequency signal (i.e., chirp signal) is sampled by using the sampling rate fs, so that each intermediate frequency signal (i.e., chirp signal) obtains K sampling points.

And continuously performing two-dimensional fast Fourier transform (namely performing 2D-FFT on the echo intermediate frequency signals of each frame) on the N echo intermediate frequency signals of the M groups respectively to obtain one-dimensional range profiles of the N scenes of the M groups.

And then, overlapping the N one-dimensional range profiles in each group to obtain M coherent and overlapped one-dimensional range profiles, wherein the range profiles correspond to a zero Doppler channel (namely, an object corresponding to zero-speed, namely, an object which is relatively static with the radar) in the radar Doppler processing.

Extracting phase from each range unit of the one-dimensional range image after the M coherent superposition, and unwrapping the phase of each range unit in the slow time dimension to obtain the real phase, wherein the real phase range can be [ (-pi, pi), (-infinity, + ∞) ] and can be set according to the actual situation.

The unwrapped phases for each range bin are then high-pass filtered to remove low frequency components, resulting in an M × K matrix S1 (i.e., "rows" in the matrix S1 represent the phase dimension and "columns" represent the distance dimension).

FFT is performed on each column of the matrix S1, and a power spectrum is obtained, and a ratio of power of a point (all points) in each column to total power of the column is calculated to obtain an M × K matrix S2 (i.e., "row" in the matrix S2 represents a distance dimension, and "column" represents a column power spectrum ratio dimension).

For the matrix S2, the maximum value of the power spectrum ratio of each column and the entropy value of each column may be calculated; and the column with the maximum power spectrum ratio and the minimum entropy value can be used as the position of the physical sign point, so that the physical sign point can be positioned.

In addition, the real-time tracking of the positions of the physical sign points can be realized by circularly executing the steps.

In the above embodiment, by combining the power spectrum ratio and the entropy, not only the position of the physical sign point can be accurately located, the physical sign point of the human body can be accurately found even in a complex scene, but also the position of the physical sign point can be tracked in real time, and meanwhile, when the position of the human body changes, the physical sign point of the human body can be relocated, so that the detection failure caused by the change of the position of the human body is avoided.

It should be noted that, since the power spectrum ratio is the largest, and some deviations sometimes occur when the entropy value is the smallest, 3 or 4 points (i.e. elements) with the smallest entropy value can be used as the sign points.

After the sign point is located, the respiration rate may be obtained by obtaining a slow time phase power spectrum V1 at the sign point, extracting a plurality of columns around the sign point (for example, if the column of the sign point is the 4 th column, 2, 3, or 5 columns may be extracted), and accumulating to obtain an accumulated slow time phase power spectrum V2.

In the slow time phase power spectrum V1, the maximum power value in the breathing frequency band (e.g., 0.15-0.5Hz) can be found, and the frequency point of the maximum power value is multiplied by 60 (i.e., one minute includes 60 seconds) to be used as the breathing rate (times/minute).

In addition, because the heartbeat amplitude is weak, in the echo of the millimeter wave radar, the heartbeat signal is easily submerged in other interference signals such as respiration, and therefore how to more accurately detect the heart rate is a difficulty in detecting the millimeter wave vital sign. Aiming at the difficulty, in the embodiment of the invention, the heartbeat detection capability of the millimeter wave radar can be enhanced by integrating and analyzing the distance units around the sign points; specifically, the method for acquiring the heart rate may be:

based on the above embodiment, in the slow time phase power spectrum V2, based on the current M groups of signals, the values in the heartbeat frequency band or the heartbeat frequency band (e.g., 0.9-2Hz) and the values in the heartbeat frequency band or the heartbeat frequency band corresponding to the previous V2 obtained by the same method are accumulated to obtain the vector V3. That is, the echo signal includes a plurality of M groups (frames) of signals, the same operation may be performed for each of the M groups (frames), and the values obtained by the operations are added up to obtain the vector V3. Then, the maximum value in the vector V3 is searched continuously, and the frequency point of the maximum value is multiplied by 60, and then the frequency point can be output as the heart rate or the pulse rate.

It should be noted that the preset values, the preset conditions and other parameters or conditions that can be set in advance in the embodiment of the present application can be adaptively adjusted based on actual requirements; meanwhile, the rows and columns in each matrix can be interchanged based on actual requirements and can be flexibly used.

EXAMPLE III

Fig. 3 is a block diagram of a device for detecting vital sign parameters according to a third embodiment of the present invention, which is capable of performing a method for detecting vital sign parameters according to any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the method for performing the method. As shown in fig. 3, the apparatus specifically includes:

an intermediate frequency signal determining module 301, configured to determine an echo intermediate frequency signal of an echo signal frame according to a transmission signal of at least two groups of transmission signal frames and an echo signal of at least two groups of echo signal frames;

a target range profile determining module 302, configured to determine a target one-dimensional range profile between any group of echo signal frames and at least one object to be measured based on fast fourier transform according to echo intermediate frequency signals of the echo signal frames;

a first matrix determining module 303, configured to filter an actual phase of a sampling point in the target one-dimensional range profile according to a preset phase extraction method, to obtain a first matrix used for representing a target phase of the sampling point;

a second matrix determining module 304, configured to determine, according to a preset power spectrum determination algorithm, a power spectrum ratio of power of each element in the first matrix to total power of a column in which the element is located, so as to obtain a second matrix;

a target point determining module 305, configured to determine a target sign point in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determining rule, so as to obtain a vital sign parameter at the target sign point.

Optionally, the intermediate frequency signal determining module 301 is specifically configured to:

receiving at least two groups of echo signal frames associated with a transmitted signal frame; the number of the groups of the transmitting signal frames is the same as that of the echo signal frames, at least two echo signals exist in one group of echo signal frames, and the number of the transmitting signals in one group of transmitting signal frames is the same as that of the echo signals in one group of echo signal frames;

according to a transmitting signal of a transmitting signal frame, carrying out difference frequency processing on an echo signal in an echo signal frame associated with the transmitting signal frame to obtain an echo intermediate frequency signal; wherein, the number of echo intermediate frequency signals is the same as the number of echo signals.

Optionally, the target range profile determining module 302 is specifically configured to:

performing fast Fourier transform on any echo intermediate frequency signal in at least two groups of echo signal frames to obtain an initial one-dimensional range profile of the echo intermediate frequency signal;

and carrying out coherent superposition processing on at least two initial one-dimensional range profiles in each group of echo signal frames to obtain a target one-dimensional range profile corresponding to each group of echo signal frames.

Optionally, the first matrix determining module 303 is specifically configured to:

extracting the current phase of the sampling point according to the target one-dimensional range profile;

unwrapping the current phase of the sampling point in a slow time dimension to obtain the actual phase of the sampling point;

carrying out high-pass filtering on the actual phase of the sampling point, and filtering low-frequency components in the actual phase to obtain a target phase of the sampling point;

generating a first matrix according to the target phase of the sampling point; the number of rows of the first matrix is the same as the number of groups of echo signal frames, and the number of columns of the first matrix is the same as the number of sampling points.

Optionally, the second matrix determining module 304 is specifically configured to:

carrying out fast Fourier transform on any column phase value in the first matrix, and obtaining a power spectrum of any column phase value in the first matrix according to a preset power spectrum calculation formula;

determining the power spectrum ratio of the power of each element in any column to the total power of the column in which the element is located according to the power spectrum of the phase value of any column;

generating a second matrix according to the power spectrum ratio; the number of rows of the second matrix is the same as the number of groups of echo signal frames, and the number of columns of the second matrix is the same as the number of sampling points.

Optionally, the target point determining module 305 is specifically configured to:

determining the maximum value of any column of power spectrum ratio and the entropy value of any column in the second matrix according to the power spectrum ratio in the second matrix, taking the maximum value of any column of power spectrum ratio as a candidate maximum value, and taking the entropy value of any column as a candidate entropy value;

selecting a target maximum value from the candidate maximum values according to a preset sign point determination rule;

determining whether the candidate entropy value of the column where the target maximum value is located meets a preset sign point determination rule;

and if so, determining the sampling points of the column where the target maximum value is located as target sign points.

Optionally, the apparatus further comprises:

a current first column determining module, configured to extract a column of the target sign point in the second matrix as a current first column after determining the target sign point in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determining rule;

and the breathing rate determining module is used for determining the target breathing rate of the target sign point from the current first column according to a preset breathing rate determining rule.

Optionally, the respiration rate determining module is specifically configured to:

acquiring a current breathing power value in a preset breathing frequency band in the current first column;

selecting a first power value satisfying a preset first power determination condition from the current breathing power values;

and multiplying the frequency point of the first power value by a preset value to serve as the target respiration rate of the target physical sign point.

Optionally, the apparatus further comprises:

a current second column determining module, configured to, after extracting a column of the target sign point in the second matrix as a current first column, extract, according to a preset column extraction rule, a preset number of columns from the second matrix as a current second column;

a current third column determining module, configured to add the current first column to the current second column to obtain a current third column;

a current power spectrum row determining module, configured to obtain a current heartbeat power value in a preset heartbeat frequency band in the current third row, and generate a current heartbeat power spectrum row;

the historical power spectrum column determining module is used for acquiring a historical heartbeat power value in a preset heartbeat frequency band in a historical third column to generate a historical heartbeat power spectrum column;

a current fourth column determining module, configured to accumulate elements of the current heartbeat power spectrum column and elements of the historical heartbeat power spectrum column of the corresponding row to obtain a current fourth column;

and the heartbeat rate determining module is used for determining the target heartbeat rate of the target sign point from the current fourth column according to a preset heartbeat rate determining rule.

Optionally, the heartbeat rate determining module is specifically configured to:

selecting a second power value meeting a preset second power determination condition from the current fourth column;

and multiplying the frequency point of the second power value by a preset value to serve as the target heart rate of the target physical sign point.

According to the embodiment of the invention, echo signals are processed, each group of echo signal frames corresponds to one target one-dimensional range profile, and the phases of sampling points are filtered according to the target one-dimensional range profiles to generate a first matrix. Through filtering the phase place, can reduce the influence of a plurality of interferents to target sign point, first matrix is used for expressing the phase value of each sampling point after the filtering. According to the first matrix, a second matrix representing the power spectrum ratio is generated, and the target sign point is selected from the second matrix according to the power spectrum ratio, so that the problem that the target sign point is inaccurate due to the fact that the target sign point is determined through the one-dimensional range profile is solved. According to the embodiment of the invention, the first matrix and the second matrix are generated, so that the interference of a plurality of objects in the environment is avoided, the determination precision of the target sign point is improved, other vital sign parameters are obtained according to the target sign point, and the determination efficiency and the determination precision of the vital sign parameters are improved.

Example four

Fig. 4 is a schematic structural diagram of a detection apparatus according to a fourth embodiment of the present invention. The detection device of vital signs parameters and vital signs points may be a computer device, and fig. 4 shows a block diagram of an exemplary computer device 400 suitable for implementing an embodiment of the invention. The computer device 400 shown in fig. 4 is only an example and should not bring any limitations to the functionality or scope of use of the embodiments of the present invention.

As shown in fig. 4, computer device 400 is in the form of a general purpose computing device. The components of computer device 400 may include, but are not limited to: one or more processors or processing units 401, a system memory 402, and a bus 403 that couples the various system components (including the system memory 402 and the processing unit 401).

Bus 403 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, such architectures include, but are not limited to, Industry Standard Architecture (ISA) bus, micro-channel architecture (MAC) bus, enhanced ISA bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.

Computer device 400 typically includes a variety of computer system readable media. Such media can be any available media that is accessible by computer device 400 and includes both volatile and nonvolatile media, removable and non-removable media.

The system memory 402 may include computer system readable media in the form of volatile memory, such as Random Access Memory (RAM)404 and/or cache memory 405. The computer device 400 may further include other removable/non-removable, volatile/nonvolatile computer system storage media. By way of example only, storage system 406 may be used to read from and write to non-removable, nonvolatile magnetic media (not shown in FIG. 4, and commonly referred to as a "hard drive"). Although not shown in FIG. 4, a magnetic disk drive for reading from and writing to a removable, nonvolatile magnetic disk (e.g., a "floppy disk") and an optical disk drive for reading from or writing to a removable, nonvolatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus 403 by one or more data media interfaces. Memory 402 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention.

A program/utility 408 having a set (at least one) of program modules 407 may be stored, for example, in memory 402, such program modules 407 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which examples or some combination thereof may comprise an implementation of a network environment. Program modules 407 generally perform the functions and/or methods of the described embodiments of the invention.

The computer device 400 may also communicate with one or more external devices 409 (e.g., keyboard, pointing device, display 410, etc.), with one or more devices that enable a user to interact with the computer device 400, and/or with any devices (e.g., network card, modem, etc.) that enable the computer device 400 to communicate with one or more other computing devices. Such communication may be through input/output (I/O) interface 411. Moreover, computer device 400 may also communicate with one or more networks (e.g., a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network such as the Internet) via network adapter 412. As shown in FIG. 4, network adapter 412 communicates with the other modules of computer device 400 via bus 403. It should be appreciated that although not shown in FIG. 4, other hardware and/or software modules may be used in conjunction with computer device 400, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, among others.

The processing unit 401 executes various functional applications and data processing by running the program stored in the system memory 402, for example, implementing a method for detecting vital sign parameters provided by the embodiment of the present invention, including:

filtering the actual phase of the sampling point in the target one-dimensional range profile according to a preset phase extraction method to obtain a first matrix representing the target phase of the sampling point;

EXAMPLE five

The fifth embodiment of the present invention further provides a storage medium containing computer-executable instructions, where the storage medium stores a computer program, and when the computer program is executed by a processor, the method for detecting vital sign parameters according to the fifth embodiment of the present invention is implemented, where the method includes:

Computer storage media for embodiments of the invention may employ any combination of one or more computer-readable media. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer-readable storage medium may be, for example, but is not limited to: an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet service provider).

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for detecting vital sign parameters is characterized by comprising the following steps:

2. The method of claim 1, wherein determining the echo intermediate frequency signal of the echo signal frame according to the transmission signal of at least two sets of transmission signal frames and the echo signal of at least two sets of echo signal frames comprises:

3. The method of claim 1, wherein determining a one-dimensional range profile of the target between any group of echo signal frames and at least one object to be measured based on fast fourier transform according to echo intermediate frequency signals of the echo signal frames comprises:

4. The method according to claim 1, wherein filtering actual phases of the sampling points in the target one-dimensional range profile according to a preset phase extraction method to obtain a first matrix for representing target phases of the sampling points, comprises:

5. The method of claim 1, wherein determining a power spectrum ratio of the power of each element in the first matrix to the total power of the column in which the element is located according to a predetermined power spectrum determination algorithm to obtain the second matrix comprises:

6. The method according to claim 1, wherein determining the target sign point in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determination rule comprises:

7. The method according to claim 1, after determining the target sign point in the sampling points according to the power spectrum ratio in the second matrix and a preset sign point determination rule, further comprising:

extracting columns of the target sign points in the second matrix as current first columns;

and determining the target respiration rate of the target sign point from the current first column according to a preset respiration rate determination rule.

8. The method according to claim 7, wherein determining a target respiration rate of a target vital point from the current first column according to a preset respiration rate determination rule comprises:

9. The method according to claim 7, wherein after extracting a column of a target sign point in the second matrix as a current first column, further comprising:

extracting a preset number of columns from the second matrix as a current second column according to a preset column extraction rule;

adding the current first column and the current second column to obtain a current third column;

acquiring a current heartbeat power value in a preset heartbeat frequency band in the current third row to generate a current heartbeat power spectrum row;

acquiring historical heartbeat power values in a preset heartbeat frequency band in a historical third column to generate a historical heartbeat power spectrum column;

accumulating the elements of the current heartbeat power spectrum column and the elements of the historical heartbeat power spectrum column of the corresponding row to obtain a current fourth column;

and determining the target heart rate of the target sign point from the current fourth column according to a preset heart rate determination rule.

10. The method according to claim 9, wherein determining the target heart rate of the target vital sign point from the current fourth column according to a preset heart rate determination rule comprises:

11. An apparatus for detecting a vital sign parameter, comprising:

12. A method of detecting a point of a vital sign, comprising:

wherein M, N, K are all positive integers greater than or equal to 2.

13. The method of claim 12, wherein the FMCW sensor is applied; the signal processing of the echo signal to obtain one-dimensional range profile data includes:

wherein the unit signal is a chirp signal.

14. The method of claim 13, wherein the unwrapping each range cell in the slow time dimension to obtain a matrix of M x K phase distances S1, comprises:

15. The method of claim 13, wherein the matrix S1 has a row phase dimension, a column distance dimension; the obtaining of the power spectrum ratio of each element in the distance dimension based on the matrix S1 to obtain a distance power spectrum ratio matrix S2 of M × K includes:

16. The method of claim 13, wherein the matrix S2 has a row distance dimension, a column power spectrum ratio dimension; in the matrix S2, taking at least one element, as the sign point, of which the power spectrum ratio is maximum in the power spectrum ratio dimension and the entropy value satisfies the preset condition, the method includes:

obtaining an entropy value of each column in the matrix S2; and

17. The method according to claim 16, wherein the preset condition is that a predetermined number of columns are arranged at the rearmost in order of entropy values from large to small;

wherein the predetermined number is greater than or equal to 1.

18. The method of claim 17, wherein the predetermined number is 3.

19. A method of tracking a vital sign point, comprising:

cyclically repeating the method of any one of claims 1-18 for real-time tracking of the vital sign points.

20. A method of obtaining a respiratory rate, comprising:

obtaining the sign points using the method of any one of claims 1-18;

21. The method of claim 20, wherein the predetermined breathing frequency range is 0.15-0.5 Hz; and/or

The obtaining of the maximum power value within a preset respiratory frequency band in the slow time phase power spectrum V1 to obtain the respiratory rate includes:

22. A method of acquiring a heart rate, comprising:

obtaining the sign points using the method of any one of claims 1-18;

accumulating values in a preset heart rate frequency band acquired from the slow time phase power spectrum V2 to obtain a vector spectrum V3; and

23. The method of claim 22, wherein the predetermined heart rate frequency band is 0.9-2 Hz; and/or

The obtaining of the frequency point corresponding to the maximum value in the vector spectrum V3 to obtain the heart rate includes:

24. The method of claim 22 or 23, wherein the heart rate frequency band comprises a heartbeat frequency band and/or a pulsatile frequency band.

25. The method of claim 24, wherein when the heart rate frequency band comprises a heartbeat frequency band and a pulsatile frequency band, the method further comprises:

26. A detection apparatus comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any one of claims 1-10, 12-25 when executing the program.

27. A storage medium containing computer-executable instructions for performing the method of any one of claims 1-10, 12-25 when executed by a computer processor.