Pulse wave conduction velocity determination method and device executed by electronic equipment

Abstract

The invention provides a pulse wave conduction velocity determination method executed by electronic equipment, which can be applied to the technical field of intelligent perception. The pulse wave conduction velocity determination method executed by the electronic equipment comprises the following steps: acquiring a first reference signal for representing a vibration rule of a first part of a detected object; acquiring a second reference signal for representing the vibration law of a second part of the measured object; on the basis of the first reference signal and the second reference signal, calculating conduction time of the pulse wave from the first part to the second part; calculating the conduction distance of the pulse wave from the first part to the second part; and calculating the target pulse wave conduction velocity based on the conduction time and the conduction distance. The invention further provides a pulse wave conduction velocity determination device executed by the electronic equipment.

Description

Technical Field

[0001] The present invention relates to the field of intelligent sensing technology, and in particular to a method and device for determining pulse wave velocity executed by an electronic device. Background Art

[0002] Currently, the methods for measuring pulse wave velocity can be divided into two categories: invasive methods and non-invasive methods. Non-invasive methods mainly measure the pulse wave transmission time (Pulse Transit Time, abbreviated as PTT) to obtain the pulse wave transmission velocity (Pulse Wave Velocity, abbreviated as PWV).

[0003] In the process of realizing the concept of the present invention, the inventors found that there are at least the following problems in the related art: (1) For invasive methods, the operation is complicated and the cost is relatively high. It has high requirements for technical equipment and personnel skills, and it causes greater trauma and risks to the object being measured. (2) For non-invasive methods, the object being measured usually needs to wear a contact sensor to obtain the electrocardiogram or peripheral arterial pressure waveform signal of the object being measured, and the contact sensor may not be suitable for people with skin problems such as skin burns. Summary of the invention

[0004] In view of the above problems, the present invention provides a method and apparatus for determining pulse wave velocity performed by an electronic device.

[0005] One aspect of the present invention provides a method for determining pulse wave conduction velocity performed by an electronic device, comprising: obtaining a first reference signal for characterizing the vibration law of a first part of a measured object, wherein the first reference signal is obtained by processing a first original signal, and the first original signal includes a millimeter-wave radar echo signal reflected by the first part of the measured object; obtaining a second reference signal for characterizing the vibration law of a second part of the measured object, wherein the second reference signal is obtained by processing the second original signal, and the second original signal includes a millimeter-wave radar echo signal reflected by the second part of the measured object; based on the first reference signal and the second reference signal, calculating the conduction time of the pulse wave from the first part to the second part; calculating the conduction distance of the pulse wave from the first part to the second part; and calculating the target pulse wave conduction velocity based on the conduction time and the conduction distance.

[0006] According to an embodiment of the present invention, the pulse wave velocity determination method performed by the electronic device also includes: determining a reference pulse wave velocity corresponding to the first part and the second part; and generating a reference classification result related to the object under test based on the target pulse wave velocity and the reference pulse wave velocity.

[0007] According to an embodiment of the present invention, the first part includes: the heart part, or other predetermined parts other than the heart part; the second part includes: other predetermined parts other than the heart part, and the first part is different from the second part; when the first part includes the heart part, based on the first reference signal and the second reference signal, calculating the conduction time of the pulse wave from the first part to the second part includes: performing differential processing on the first reference signal to generate a cardiac oscillation signal; based on the heartbeat cycle, dividing the cardiac oscillation signal into multiple cardiac oscillation signal segments; based on the pulse wave cycle, dividing the second reference signal into multiple pulse wave signal segments, wherein the multiple cardiac oscillation signal segments correspond one-to-one to the multiple pulse wave signal segments; based on the multiple cardiac oscillation signal segments and the multiple pulse wave signal segments, calculating the conduction time of the pulse wave from the first part to the second part.

[0008] According to an embodiment of the present invention, based on multiple cardiac oscillation signal segments and multiple pulse wave signal segments, calculating the conduction time of the pulse wave from a first site to a second site includes: for each cardiac oscillation signal segment, selecting an aortic valve opening signal point from each cardiac oscillation signal segment; for each cardiac oscillation signal segment, determining a first moment corresponding to the aortic valve opening signal point; for each pulse wave signal segment, determining a pulse wave signal starting signal point corresponding to each pulse wave signal segment; for each pulse wave signal segment, determining a second moment corresponding to the pulse wave signal starting signal point; based on the first moment and the second moment, calculating the conduction time of the pulse wave from the first site to the second site.

[0009] According to an embodiment of the present invention, based on the first moment and the second moment, calculating the conduction time of the pulse wave from the first part to the second part includes: performing a first abnormal value elimination process on each first moment and each second moment respectively to obtain a first target moment and a second target moment; for each first target moment, calculating a first time difference between the second target time corresponding to the first target moment and the first target moment; calculating the average value of each first time difference to obtain the conduction time of the pulse wave from the first part to the second part.

[0010] According to an embodiment of the present invention, in the case where the first part includes other predetermined parts except the heart part, calculating the conduction time of the pulse wave from the first part to the second part based on the first reference signal and the second reference signal includes: dividing the first reference signal into a plurality of first pulse wave signal segments based on the pulse wave cycle, and dividing the second reference signal into a plurality of second pulse wave signal segments, wherein the plurality of first pulse wave signal segments correspond one-to-one to the plurality of second pulse wave signal segments; determining a first starting signal point corresponding to each first pulse wave signal segment, and determining a second starting signal point corresponding to each second pulse wave signal segment; determining a third moment corresponding to the first starting signal point, and a fourth moment corresponding to the second starting signal point; and calculating the conduction time of the pulse wave from the first part to the second part based on the third moment and the fourth moment.

[0011] According to an embodiment of the present invention, based on the third moment and the fourth moment, calculating the conduction time of the pulse wave from the first part to the second part includes: performing a second outlier elimination process on each third moment and each fourth moment to obtain a third target moment and a fourth target moment; for each third target moment, calculating a second time difference between the fourth target time corresponding to the third target moment and the third target moment; calculating the average of each second time difference to obtain the conduction time of the pulse wave from the first part to the second part.

[0012] According to an embodiment of the present invention, the pulse wave velocity determination method performed by the electronic device also includes: performing interference suppression processing on the first original signal and the second original signal respectively to eliminate the influence of the millimeter-wave radar echo signal reflected by other parts except the first part and the second part, and obtain a first candidate signal and a second candidate signal; based on the transmission distance and transmission angle of the millimeter-wave radar, screening out a first range of interest from the first part, and screening out a second range of interest from the second part; determining a first preliminary signal corresponding to the first range of interest from the first candidate signal, and determining a second preliminary signal corresponding to the second range of interest from the second candidate signal; based on a predetermined signal quality standard, screening out a first reference signal from the first preliminary signal, and screening out a second reference signal from the second preliminary signal.

[0013] According to an embodiment of the present invention, calculating the conduction distance of the pulse wave from a first part to a second part includes: determining the straight-line distance between the first part and the second part; and calculating the conduction distance of the pulse wave from the first part to the second part based on a predetermined correction coefficient and the straight-line distance.

[0014] Another aspect of the present invention provides a pulse wave velocity determination device, comprising: a first millimeter wave radar, used to transmit a millimeter wave radar signal to a first part of an object under test; a second millimeter wave radar, used to transmit a millimeter wave radar signal to a second part of the object under test, wherein the first millimeter wave radar and the second millimeter wave radar are connected via a circuit; an electronic device, comprising: one or more processors; a memory, used to store one or more computer programs, characterized in that the one or more processors execute one or more computer programs to implement the steps of the pulse wave velocity determination method performed by the electronic device.

[0015] According to the embodiment of the present invention, the pulse wave velocity is determined based on the millimeter wave radar echo signal reflected by the first part and the second part of the measured object, and the measured object does not need to wear a contact sensor, thereby realizing the non-contact determination of the pulse wave velocity. Since the measured object does not need to wear a contact sensor and does not need to squeeze the blood vessel, the test process is more comfortable and convenient, thereby improving the efficiency and applicability of the process of determining the pulse wave velocity, and the determination result will not be interfered by the pre-ejection period.

[0016] In addition, there is no restriction on the detection site when the first original signal and the second original signal are obtained by millimeter wave radar. It can measure not only the heart, but also other parts with arteries close to the skin surface, such as limbs, neck, ankles, etc. By selecting different measurement sites, multiple measurement combinations such as peripheral arteries, aorta, "peripheral arteries + aorta" can be achieved, which broadens the application scope of the pulse wave velocity determination method. Furthermore, by determining the pulse wave velocity through millimeter wave radar, the equipment composition is simpler, the cost is lower, and the use and maintenance are more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0018] Figure 1 A flowchart of a pulse wave velocity determination method performed by an electronic device according to an embodiment of the present invention is schematically shown;

[0019] Figure 2 A schematic diagram schematically shows a method of generating a reference classification result related to a measured object according to an embodiment of the present invention;

[0020] Figure 3 A schematic diagram schematically shows a first original signal and a second original signal according to an embodiment of the present invention;

[0021] Figure 4 A schematic diagram schematically shows a first reference signal and a second reference signal according to an embodiment of the present invention;

[0022] Figure 5 A flowchart of a pulse wave velocity determination method executed by an electronic device according to another embodiment of the present invention is schematically shown;

[0023] Figure 6 The system structure diagram of the pulse wave velocity determination device executed by an electronic device according to an embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0024] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0025] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0026] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0027] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0028] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. If the full text involves descriptions such as "first", "second", etc., the descriptions such as "first", "second", etc. are only used to distinguish similar objects, and cannot be understood as indicating or implying their relative importance, order of precedence, or implicitly indicating the number of technical features indicated. It should be understood that the data described by "first", "second", etc. can be interchangeable under appropriate circumstances.

[0029] Atherosclerosis refers to changes in the stiffness of the arterial wall due to changes in the mechanical properties of the arteries. It is an important sign of vascular damage and can be used to predict cardiovascular disease. Daily monitoring of vascular health is of great significance for the prevention and early warning of cardiovascular disease. Arterial stiffness is an independent predictor of cardiovascular disease and all-cause mortality in different populations and has important clinical value. From the perspective of the biophysical relationship between arterial wall stress and strain, pulse wave velocity can be used as an intermediate result and as a reference for detecting arteriosclerosis, especially for detecting large catheter artery sclerosis.

[0030] The pulse wave velocity can be determined based on the pulse wave conduction time. Related methods for measuring the pulse wave conduction time include the two-point non-invasive method. The two-point non-invasive method includes the electrocardiogram R wave method. This method uses the peak of the electrocardiogram R wave as the conduction time starting point, the pulse wave characteristic point with the same cycle as the electrocardiogram R wave measured somewhere in the peripheral artery as the conduction time end point, and the time interval between the conduction time starting point and the conduction time end point is the pulse wave conduction time.

[0031] The two-point non-invasive method also includes obtaining peripheral arterial pressure waveform signals at two different measurement sites of the human body. The time interval between the two peripheral arterial pressure waveform signals is the pulse wave conduction time. The measurement sites can be the central elastic aorta, the aorta, and the peripheral muscle arteries. For example, the pulse wave conduction velocity (cfPWV) for the carotid artery and the femoral artery can be obtained, and the pulse wave conduction velocity (baPWV) for the brachial artery to the ankle artery can also be obtained. Among them, the methods for collecting pulse waves at peripheral arterial points include tension measurement, ultrasonic Doppler method, photoelectric volumetric pulse wave method, etc.

[0032] In the process of implementing the present invention, it is found that for the electrocardiogram R wave method, it is necessary to measure the electrocardiogram and the pulse wave of a certain part of the body at the same time, so more sensors are required, the equipment is more complicated, and the measurement results will be interfered by the pre-ejection period (PEP). The measurement of the peripheral arterial pressure waveform signal usually requires the use of a cuff and a tonometer to obtain the pulse wave of the peripheral artery. However, the cuff can only be used to measure the limited positions of the limbs, and the blood flow needs to be blocked by pressure during measurement, resulting in low measurement comfort. The threshold for using the tonometer is high and professional training is required. In addition, the subject usually needs to wear a cuff, a tonometer, an electrode and other contact sensors to obtain the electrocardiogram or peripheral arterial pressure waveform signal of the subject, and the contact sensor may not be suitable for people with skin problems such as skin burns. In the experimental process of implementing the present invention, it was found that when the pulse wave conduction velocity is determined based on the millimeter wave radar signal, the subject does not need to wear a contact sensor, thereby realizing the determination of the pulse wave conduction velocity in a non-contact manner.

[0033] On this basis, the present invention provides a method for determining pulse wave velocity performed by an electronic device.

[0034] Figure 1 The flowchart of the pulse wave velocity determination method executed by an electronic device according to an embodiment of the present invention is schematically shown.

[0035] like Figure 1 As shown, the pulse wave velocity determination method performed by the electronic device in this embodiment includes operations S110 to S150.

[0036] In operation S110, a first reference signal for characterizing a vibration law of a first part of the measured object is obtained, wherein the first reference signal is obtained by processing a first original signal, and the first original signal includes a millimeter-wave radar echo signal reflected by the first part of the measured object.

[0037] In operation S120, a second reference signal for characterizing the vibration law of a second part of the measured object is obtained, wherein the second reference signal is obtained by processing a second original signal, and the second original signal includes a millimeter wave radar echo signal reflected by the second part of the measured object.

[0038] According to an embodiment of the present invention, the first part may be, for example, the heart of the subject, or a part where an artery is close to the skin surface, such as the radial artery at the wrist, or other parts where an artery is present, such as the limbs, neck, ankle, etc. of the subject. The second part is a part different from the first part and where an artery is close to the skin surface.

[0039] Heartbeats and arterial pulsations can cause weak, regular vibrations in the skin on the surface of the body. These vibrations can cause phase changes in the millimeter-wave radar echo signal. Therefore, based on the above phase changes, the signal caused by the vibration of the first part and the signal caused by the vibration of the second part can be obtained from the received millimeter-wave radar echo signal.

[0040] Specifically, the person being measured can lie flat in a supine position and rest. One millimeter-wave radar can be placed near the first part, and another millimeter-wave radar can be placed near the second part, and the two millimeter-wave radars need to face the first part and the second part respectively. The distance between the millimeter-wave radar and the first part and the second part can be, for example, 10 to 60 centimeters. The millimeter-wave radar can transmit a frequency-modulated continuous wave signal to the person being measured and receive the millimeter-wave radar echo signal, thereby forming a single complete transceiver process.

[0041] The time window length can be preset, and the millimeter wave radar echo signal reflected by the first part of the measured object in the preset time window is collected and cached to obtain the first original signal, and the millimeter wave radar echo signal reflected by the second part of the measured object in the preset time window is collected and cached to obtain the second original signal. The preset time window can be, for example, 5 to 30 seconds. As a preference, the preset time window can be, for example, 5 to 20 seconds. The heart usually beats 60 to 100 times per minute. When the length of the preset time window is too short, the number of heartbeats collected is too small, and the heartbeat law or arterial pulsation law cannot be accurately analyzed; when the length of the preset time window is too long, the measured object may not be able to lie flat and rest, resulting in the collected millimeter wave radar echo signal being unable to accurately reflect the heartbeat law or arterial pulsation law. Further, the first original signal and the second original signal can be the timing phase sequence of the millimeter wave radar echo signal reflected by the first part and the second part of the measured object within the preset time.

[0042] According to an embodiment of the present invention, the first original signal and the second original signal may contain noise signals, or millimeter-wave radar echo signals reflected from areas other than the first part and the second part. Therefore, the first original signal and the second original signal need to be processed to obtain a signal that can accurately characterize the vibration law of the first part of the object under test, and a signal that can accurately characterize the vibration law of the second part, that is, the first reference signal and the second reference signal.

[0043] In operation S130, a transmission time of a pulse wave from a first site to a second site may be calculated based on the first reference signal and the second reference signal.

[0044] The pulse wave is a pressure wave generated when blood is pumped into the arterial system each time the heart contracts. Each heartbeat can generate a pulse wave, and the generated pulse wave can be transmitted along the artery, for example, from the aorta to the peripheral artery. The conduction process of the pulse wave takes a certain amount of time. For example, it takes a certain amount of time for the pulse wave to be transmitted from the first part to the second part, resulting in a time difference between the first reference signal and the second reference signal of the same period.

[0045] For example: a pulse wave is generated when the heart beats. The pulse wave generated by this heartbeat can be transmitted from the first part to the second part along the artery. When the pulse wave is transmitted to the first part, it will cause a weak vibration on the surface of the first part, thereby obtaining a first original signal. The first reference signal can be obtained by processing the first original signal; when the pulse wave is transmitted from the first part to the second part, it will cause a weak vibration on the surface of the second part, thereby obtaining a second original signal. The second reference signal can be processed to obtain a second reference signal. Since the first reference signal and the second reference signal are both caused by the same pulse wave, the first reference signal and the second reference signal are signals of the same period. Since it takes time for the pulse wave to be transmitted from the first part to the second part, there is a time difference between the first reference signal and the second reference signal.

[0046] According to an embodiment of the present invention, the conduction time of the pulse wave from the first site to the second site may be determined based on the time difference between the first reference signal and the second reference signal.

[0047] In operation S140, a conduction distance of the pulse wave from the first site to the second site may be calculated.

[0048] According to an embodiment of the present invention, the conduction distance of the pulse wave from the first site to the second site may be the length of the arterial blood vessel between the first site and the second site.

[0049] In operation S150, a target pulse wave velocity is calculated based on the transmission time and the transmission distance.

[0050] According to an embodiment of the present invention, the target pulse wave velocity can be calculated, for example, by formula (1).

[0051] (1)

[0052] Among them, PWV is the target pulse wave velocity, L is the conduction distance, and PTT is the conduction time.

[0053] It should be noted that the target pulse wave velocity obtained here is only a reference information for medical staff to make a diagnosis, and is not a direct diagnosis result, and the above-mentioned pulse wave velocity determination method can be executed by an electronic device.

[0054] According to the embodiment of the present invention, the pulse wave velocity is determined based on the millimeter wave radar echo signal reflected by the first part and the second part of the measured object, and the measured object does not need to wear a contact sensor, thereby realizing the non-contact determination of the pulse wave velocity. Since the measured object does not need to wear a contact sensor and does not need to squeeze the blood vessel, the test process is more comfortable and convenient, thereby improving the efficiency and applicability of the process of determining the pulse wave velocity.

[0055] In addition, there is no restriction on the detection site when the first original signal and the second original signal are obtained by millimeter wave radar. It can measure not only the heart, but also other parts with arteries close to the skin surface, such as limbs, neck, ankles, etc. By selecting different measurement sites, multiple measurement combinations such as peripheral arteries, aorta, "peripheral arteries + aorta" can be achieved, which broadens the application scope of the pulse wave velocity determination method. Furthermore, by determining the pulse wave velocity through millimeter wave radar, the equipment composition is simpler, the cost is lower, and the use and maintenance are more convenient.

[0056] According to an embodiment of the present invention, the pulse wave velocity determination method performed by the electronic device also includes: determining a reference pulse wave velocity corresponding to the first part and the second part; and generating a reference classification result related to the object under test based on the target pulse wave velocity and the reference pulse wave velocity.

[0057] According to an embodiment of the present invention, the reference pulse wave velocity can be used to characterize the reference interval of the pulse wave velocity. The reference pulse wave velocity may be different for different ages, genders, and different body parts, so the reference pulse wave velocity corresponding to the first part and the second part can be determined, for example, the conduction velocity (cfPWV) of the pulse wave from the carotid artery to the femoral artery, or the conduction velocity (baPWV) of the pulse wave from the brachial artery to the ankle artery can be determined. Further, the reference pulse wave velocity corresponding to the first part and the second part and corresponding to the age and gender of the subject can be determined.

[0058] According to an embodiment of the present invention, the target pulse wave velocity can be compared with the reference pulse wave velocity to generate a reference classification result related to the measured object. Further, the degree of deviation of the target pulse wave velocity relative to the reference pulse wave velocity can be determined to generate a reference classification result related to the measured object.

[0059] It should be noted that the reference classification results are intermediate results and are only used as reference information for medical staff to make diagnoses, and are not direct diagnosis results.

[0060] Figure 2 A schematic diagram of generating a reference classification result related to a measured object according to an embodiment of the present invention is schematically shown.

[0061] like Figure 2 As shown, the conduction velocity of the pulse wave from the brachial artery to the ankle artery can be determined to obtain the target pulse wave conduction velocity. +1SD means that the target pulse wave conduction velocity is one standard deviation higher than the reference pulse wave conduction velocity, and -1SD means that the target pulse wave conduction velocity is one standard deviation lower than the reference pulse wave conduction velocity. Figure 2It can be seen that the reference pulse wave conduction velocity corresponding to different ages is different.

[0062] According to an embodiment of the present invention, by comparing the target pulse wave velocity with the reference pulse wave velocity, a more accurate reference classification result can be obtained.

[0063] According to an embodiment of the present invention, the first part includes: the heart part, or other predetermined parts except the heart part; the second part includes: other predetermined parts except the heart part, and the first part is different from the second part.

[0064] According to an embodiment of the present invention, other predetermined parts besides the heart may be parts where arteries are close to the skin surface, such as the radial artery at the wrist, or other parts where arteries are present, such as the limbs, neck, ankles, etc. of the subject.

[0065] According to an embodiment of the present invention, when the first site includes a heart site, calculating the conduction time of the pulse wave from the first site to the second site based on the first reference signal and the second reference signal includes operations 11 to 14.

[0066] In operation 11, differential processing may be performed on the first reference signal to generate a cardiac tremor signal.

[0067] According to an embodiment of the present invention, when the first part includes a heart part, the first reference signal can characterize the heart beat law of the measured object. The differential processing can be, for example, a second-order differential processing. By performing second-order differential processing on the first reference signal, the noise in the first reference signal can be further eliminated, the signal accuracy can be improved, and a cardiac oscillation signal can be generated. In addition, a peak value can be generated in the signal corresponding to the moment of aortic valve opening, so as to facilitate the subsequent determination of the aortic valve opening signal point from the cardiac oscillation signal.

[0068] In operation 12, the heartbeat signal may be divided into a plurality of heartbeat signal segments based on the heartbeat cycle.

[0069] According to an embodiment of the present invention, a heartbeat cycle includes a process of one contraction and one relaxation of the heart. The heartbeat signal can be divided into a plurality of heartbeat signal segments, and one heartbeat signal segment can correspond to a waveform cycle, which is used to represent a heartbeat cycle.

[0070] In operation 13, based on the pulse wave cycle, the second reference signal is divided into a plurality of pulse wave signal segments, wherein the plurality of cardiac pulsation signal segments correspond one-to-one to the plurality of pulse wave signal segments.

[0071] According to an embodiment of the present invention, the second part is a part where an artery is close to the skin surface, so the second reference signal can represent the vibration of the skin caused by the arterial pulsation. The second reference signal can be divided into multiple pulse wave signal segments, and one pulse wave signal segment is used to represent one pulse wave cycle.

[0072] When the heart beats once, it can correspond to a heartbeat signal segment, and when the pulse wave generated by this heartbeat is transmitted to the second part, it can correspond to a pulse wave signal segment. Since it takes a certain transmission time for the pulse wave to propagate in the artery, there is a time difference between the heartbeat signal segment and the pulse wave signal segment of the same period.

[0073] In operation 14 , a conduction time of the pulse wave from the first site to the second site may be calculated based on the plurality of cardiac pulsation signal segments and the plurality of pulse wave signal segments.

[0074] According to an embodiment of the present invention, specifically, based on a plurality of cardiac oscillation signal segments and a plurality of pulse wave signal segments, calculating the conduction time of the pulse wave from the first site to the second site includes operations 141 to 145 .

[0075] In operation 141 , for each cardiac pulsation signal segment, an aortic valve opening signal point is screened out from each cardiac pulsation signal segment.

[0076] When the heart contracts, the aortic valve opens, allowing blood to be pumped from the ventricles into the arteries. This process is called cardiac ejection, and cardiac ejection can generate a pulse wave. The time from ventricular electrical stimulation (corresponding to the R wave of the electrocardiogram) to the opening of the aortic valve is called the pre-ejection period. Related technologies usually use an electrocardiogram to detect the heart's electrical signals, and then use the peak of the electrocardiogram R wave as the starting point of the conduction time, and the pulse wave characteristic point with the same period as the electrocardiogram R wave measured at a certain measured point in the peripheral artery as the end point of the conduction time. The time interval between the conduction time start point and the conduction time end point is the pulse wave conduction time. However, the pulse wave conduction time measured by this method not only includes the time for blood to flow from the heart to a certain measured point in the peripheral artery, but also includes the pre-ejection period, which leads to errors in the obtained pulse wave conduction time.

[0077] According to an embodiment of the present invention, since the cardiac oscillation signal segment corresponds to the signal generated when the first part of the body surface vibrates due to the heartbeat, the cardiac oscillation signal segment does not include the signal generated in the pre-ejection period, thereby avoiding the error caused by the pre-ejection period. Furthermore, the cardiac oscillation signal segment includes the signal when the aortic valve opens, and the moment corresponding to the signal when the aortic valve opens can be used as the starting point of the conduction time, thereby making the starting point of the conduction time more accurate and reasonable, and thus accurately calculating the conduction time.

[0078] According to an embodiment of the present invention, in the cardiac pulsation signal segment, the aortic valve opening signal point may correspond to a specific signal morphology, so the aortic valve opening signal point may be determined according to the signal morphology. The signal morphology of the aortic valve opening signal point may be determined according to clinical experiments.

[0079] In operation 142, for each cardiac pulsation signal segment, a first time corresponding to the aortic valve opening signal point is determined. Specifically, the time point corresponding to the aortic valve opening signal point can be determined to obtain the first time.

[0080] In operation 143 , for each pulse wave signal segment, a pulse wave signal start signal point corresponding to each pulse wave signal segment is determined.

[0081] According to an embodiment of the present invention, a pulse wave signal segment may correspond to a pulse wave cycle, and the starting point of a pulse wave signal segment may be used as the pulse wave signal starting signal point. The pulse wave cycle may be the time interval from the start of a pulse wave generated by one heartbeat to the start of a pulse wave generated by the next heartbeat.

[0082] In operation 144, for each pulse wave signal segment, a second time corresponding to the starting signal point of the pulse wave signal is determined. Specifically, the time point corresponding to the starting signal point of the pulse wave signal can be determined to obtain the second time.

[0083] In operation 145, the conduction time of the pulse wave from the first site to the second site can be calculated based on the first time and the second time. The first time can be used as the conduction time starting point and the second time can be used as the conduction time end point to calculate the conduction time based on the conduction time starting point and the conduction time end point.

[0084] According to an embodiment of the present invention, the vibration signal of the body surface of the object under test is collected by the millimeter wave radar echo signal, from which the aortic valve opening time can be extracted. The conduction time is calculated based on the first moment corresponding to the aortic valve opening signal point, which can further avoid the interference of the pre-ejection period, thereby improving the accuracy of the conduction time.

[0085] According to an embodiment of the present invention, specifically, in operation 145 , based on the first moment and the second moment, calculating the conduction time of the pulse wave from the first site to the second site includes operations 1451 to 1453 .

[0086] In operation 1451, first outlier elimination processing is performed on each first moment and each second moment respectively to obtain a first target moment and a second target moment.

[0087] According to the embodiment of the present invention, through the first outlier elimination process, the interference moments in the first moment and the second moment can be eliminated, so that the first target moment and the second target moment are more accurate.

[0088] In operation 1452 , for each first target time, a first time difference between a second target time corresponding to the first target time and the first target time is calculated.

[0089] According to an embodiment of the present invention, since there is a one-to-one correspondence between the cardiac oscillation signal segments and the pulse wave signal segments, there is also a one-to-one correspondence between the first target time and the second target time for the cardiac oscillation signal segments and the pulse wave signal segments of the same period. The first time difference between the second target time corresponding to the first target time and the first target time can be calculated.

[0090] In operation 1453, an average value of each first time difference is calculated to obtain the conduction time of the pulse wave from the first site to the second site.

[0091] According to an embodiment of the present invention, the first time difference corresponding to each cardiac oscillation signal segment can be calculated, and the average value of all the first time differences can be calculated, so as to obtain the conduction time of the pulse wave from the first part to the second part. By calculating the average value of the first time difference corresponding to each cardiac oscillation signal segment, the interference of abnormal time difference can be eliminated, so as to improve the accuracy of conduction time. The abnormal time difference can be, for example, the maximum value, minimum value, etc. in the first time difference.

[0092] According to an embodiment of the present invention, specifically, when the first part includes other predetermined parts except the heart part, based on the first reference signal and the second reference signal, calculating the conduction time of the pulse wave from the first part to the second part includes operations 21 to 24.

[0093] In operation 21, based on the pulse wave cycle, the first reference signal is divided into a plurality of first pulse wave signal segments, and the second reference signal is divided into a plurality of second pulse wave signal segments, wherein the plurality of first pulse wave signal segments correspond one-to-one to the plurality of second pulse wave signal segments.

[0094] According to an embodiment of the present invention, when the first part includes other predetermined parts except the heart part, the first part and the second part are both parts where an artery is close to the skin surface, so the first reference signal and the second reference signal are both used to characterize the vibration generated by the body surface skin caused by arterial pulsation. The first reference signal can be divided into a plurality of first pulse wave signal segments, and the second reference signal can be divided into a plurality of second pulse wave signal segments, wherein one first pulse wave signal segment or one second pulse wave signal segment can correspond to one pulse wave cycle.

[0095] The pulse wave generated by a heartbeat can be transmitted from the first part to the second part, thereby generating a first pulse wave signal segment at the first part and a second pulse wave signal segment at the second part. The first pulse wave signal segment and the second pulse wave signal segment corresponding to the same heartbeat have a one-to-one correspondence.

[0096] In operation 22 , a first start signal point corresponding to each first pulse wave signal segment is determined, and a second start signal point corresponding to each second pulse wave signal segment is determined.

[0097] According to an embodiment of the present invention, the starting point of the first pulse wave signal segment may be used as the first starting signal point, and the starting point of the second pulse wave signal segment may be used as the second starting signal point.

[0098] In operation 23, a third time corresponding to the first start signal point and a fourth time corresponding to the second start signal point are determined. The time point corresponding to the first start signal point can be determined to obtain the third time; the time point corresponding to the second start signal point can be determined to obtain the fourth time.

[0099] In operation 24 , based on the third time and the fourth time, a conduction time of the pulse wave from the first site to the second site is calculated.

[0100] According to an embodiment of the present invention, the third moment may be used as the start point of the conduction time, and the fourth moment may be used as the end point of the conduction time to calculate the conduction time of the pulse wave from the first site to the second site.

[0101] According to an embodiment of the present invention, specifically, in operation 24 , based on the third moment and the fourth moment, calculating the conduction time of the pulse wave from the first site to the second site includes operations 241 to 243 .

[0102] In operation 241, a second outlier elimination process is performed on each third moment and each fourth moment to obtain a third target moment and a fourth target moment.

[0103] According to an embodiment of the present invention, the abnormal moments in the third moment and the fourth moment can be eliminated through the second abnormal value elimination process, so that the third target moment and the fourth target moment are more accurate. The abnormal moment can be a maximum value, a minimum value, etc. in the third target moment and the fourth target moment.

[0104] In operation 242 , for each third target time, a second time difference between a fourth target time corresponding to the third target time and the third target time is calculated.

[0105] According to the embodiment of the present invention, since there is a one-to-one correspondence between the first pulse wave signal segment and the second pulse wave signal segment corresponding to the same heartbeat, there is also a one-to-one correspondence between the third target time and the fourth target time. For each third target time, the third target time can be used as the start point of the conduction time, and the fourth target time corresponding to the third target time can be used as the end point of the conduction time to calculate the second time difference.

[0106] In operation 243, an average value of the second time differences is calculated to obtain the conduction time of the pulse wave from the first site to the second site.

[0107] According to an embodiment of the present invention, in order to eliminate the interference of abnormal time differences and improve the accuracy of conduction time, the average value of all second time differences can be calculated to obtain the conduction time of the pulse wave from the first part to the second part.

[0108] According to an embodiment of the present disclosure, when both the first reference signal and the second reference signal are used to characterize the vibrations generated by the body surface skin caused by arterial pulsation, the conduction time of the pulse wave from the first part to the second part can also be calculated based on waveform matching: a second pulse wave signal segment with the same or similar waveform as the first pulse wave signal segment can be determined, and the time difference corresponding to the first pulse wave signal segment and the second pulse wave signal segment with the same or similar waveform can be determined respectively to obtain the conduction time.

[0109] According to an embodiment of the present disclosure, since the waveforms of the signals generated by the heart and the pulse are quite different, and extracting the aortic valve opening signal point and the pulse wave signal starting signal point from the signal has high requirements on signal quality, when the signal quality is not high enough and both the first reference signal and the second reference signal are used to characterize the vibrations generated by the skin on the surface of the body caused by arterial pulsation, the conduction time can be calculated based on waveform matching.

[0110] According to an embodiment of the present invention, the pulse wave velocity determination method performed by the electronic device further includes operations 31 to 34.

[0111] In operation 31, interference suppression processing is performed on the first original signal and the second original signal respectively to eliminate the influence of the millimeter-wave radar echo signal reflected from other parts except the first part and the second part, so as to obtain the first candidate signal and the second candidate signal.

[0112] According to an embodiment of the present invention, the first original signal / the second original signal includes not only the millimeter-wave radar echo signal reflected by the first part / the second part, but may also include the millimeter-wave radar echo signal reflected by other irrelevant areas. The irrelevant areas include, for example, other parts of the measured object except the first part and the second part, and may also include environmental areas other than the measured object, such as a hospital bed.

[0113] The influence of the millimeter-wave radar echo signal reflected by the irrelevant area can be eliminated by interference suppression processing. Specifically, the interference suppression processing may include static clutter suppression and motion interference suppression. The influence of the environmental area other than the measured object can be eliminated by static clutter suppression, and the influence of the millimeter-wave radar echo signal generated by the vibration of other parts of the measured object other than the first part and the second part can be preliminarily eliminated by motion interference suppression, so as to obtain the first candidate signal and the second candidate signal.

[0114] In operation 32 , based on the transmission distance and transmission angle of the millimeter wave radar, a first range of interest is screened out from the first portion, and a second range of interest is screened out from the second portion.

[0115] According to an embodiment of the present invention, in order to further eliminate the influence of irrelevant areas, a range of interest may be further screened out from the first part and the second part.

[0116] For the first part or the second part, when the distance between the millimeter-wave radar and the measurement part is R0, the azimuth angle is θ0, and the pitch angle is φ0, the range of interest can be [(R1, R2), (θ1, θ2), (φ1, φ2)], where R1<R0,R2> R0, θ1<θ0, θ2>θ0, φ1<φ0, φ2>φ0.

[0117] In operation 33, a first preliminary selected signal corresponding to the first range of interest is determined from the first candidate signals, and a second preliminary selected signal corresponding to the second range of interest is determined from the second candidate signals.

[0118] A candidate signal corresponding to the first range of interest may be screened out from the first candidate signal, and beamforming may be performed on the candidate signal to obtain a first preliminary signal. A candidate signal corresponding to the second range of interest may also be screened out from the second candidate signal, and beamforming may be performed on the candidate signal to obtain a second preliminary signal.

[0119] According to an embodiment of the present invention, in order to determine a first reference signal / a second reference signal that can accurately characterize the vibration law of a first part / a second part of the measured object from the first preliminary signal / the second preliminary signal, in operation 34, the first reference signal can be screened out from the first preliminary signal and the second reference signal can be screened out from the second preliminary signal based on a predetermined signal quality standard.

[0120] According to an embodiment of the present invention, a predetermined signal quality standard can be used to evaluate signal quality. Based on the predetermined signal quality standard, selecting a first reference signal from the first preliminary selected signal and selecting a second reference signal from the second preliminary selected signal can be, for example: selecting a first preliminary selected signal with the best signal quality from the first preliminary selected signal to obtain a first reference signal; and selecting a second preliminary selected signal with the best signal quality from the second preliminary selected signal to obtain a second reference signal.

[0121] Figure 3 The diagram schematically shows a first original signal and a second original signal according to an embodiment of the present invention.

[0122] in, Figure 3 The horizontal axis is time, and the vertical axis is signal strength. The first original signal generated by the pulse wave velocity determination method of the present invention is shown as a green line, and the second original signal generated by the pulse wave velocity determination method of the present invention is shown as a blue line.

[0123] Figure 4 A schematic diagram of a first reference signal and a second original reference signal according to an embodiment of the present invention is schematically shown.

[0124] in, Figure 4 The horizontal axis is time, and the vertical axis is signal strength. The first reference signal generated by the pulse wave velocity determination method of the present invention is shown as a green line, and the second reference signal generated by the pulse wave velocity determination method of the present invention is shown as a blue line. Figure 4 It can be seen that there is a time difference between the first reference signal and the second reference signal.

[0125] According to an embodiment of the present invention, by performing interference suppression processing on the first original signal and the second original signal, the influence of irrelevant areas can be preliminarily eliminated; by determining a preliminary signal corresponding to the range of interest from the candidate signals, the influence of irrelevant areas can be further reduced; and based on a predetermined signal quality standard, the preliminary signal with the best signal quality is used as a reference signal, thereby obtaining a first reference signal / a second reference signal that can accurately characterize the vibration law of the first part / the second part of the measured object, thereby improving the accuracy of the target pulse wave conduction velocity.

[0126] According to an embodiment of the present invention, calculating the conduction distance of the pulse wave from a first part to a second part includes: determining the straight-line distance between the first part and the second part; and calculating the conduction distance of the pulse wave from the first part to the second part based on a predetermined correction coefficient and the straight-line distance.

[0127] The conduction distance can be calculated by formula (2).

[0128] (2)

[0129] Wherein, L is the conduction distance of the pulse wave from the first part to the second part, k is the predetermined correction coefficient, and L a is the straight-line distance between the first part and the second part, wherein the predetermined correction coefficient can be determined through clinical experiments.

[0130] Figure 5 The flowchart of a pulse wave velocity determination method executed by an electronic device according to another embodiment of the present invention is schematically shown.

[0131] like Figure 5 As shown, the pulse wave velocity determination method performed by the electronic device in this embodiment includes operations S510 to S590.

[0132] In operation S510, the person being measured lies in a supine position and rests, and millimeter wave radars are arranged at a first position and a second position respectively.

[0133] In operation S520, a first original signal and a second original signal are acquired.

[0134] In operation S530, interference suppression processing is performed on the first original signal and the second original signal to obtain a first candidate signal and a second candidate signal.

[0135] In operation S540, a first preliminary selected signal is determined from the first candidate signals, and a second preliminary selected signal is determined from the second candidate signals.

[0136] In operation S550 , a first reference signal is screened out from the first preliminary selected signal, and a second reference signal is screened out from the second preliminary selected signal.

[0137] In operation S560, a transmission time of the pulse wave from the first site to the second site is calculated based on the first reference signal and the second reference signal.

[0138] In operation S570, a conduction distance is calculated based on a straight-line distance between the first site and the second site and a predetermined correction coefficient.

[0139] In operation S580, a target pulse wave velocity is calculated based on the transmission time and the transmission distance.

[0140] In operation S590, a reference classification result related to the measured object is generated based on the target pulse wave velocity and the reference pulse wave velocity.

[0141] According to an embodiment of the present invention, a pulse wave velocity determination device includes:

[0142] A first millimeter-wave radar, used to transmit a millimeter-wave radar signal to a first part of the object to be measured;

[0143] A second millimeter-wave radar is used to transmit a millimeter-wave radar signal to a second part of the measured object, wherein the first millimeter-wave radar is connected to the second millimeter-wave radar via a circuit;

[0144] Electronic equipment, including:

[0145] one or more processors;

[0146] a memory for storing one or more computer programs,

[0147] It is characterized in that one or more processors execute one or more computer programs to implement the steps of the above-mentioned pulse wave velocity determination method.

[0148] Figure 6 The system structure diagram of the pulse wave velocity determination device executed by an electronic device according to an embodiment of the present invention is schematically shown.

[0149] like Figure 6 As shown, the first millimeter wave radar and the second millimeter wave radar are connected via a synchronization circuit so that the first millimeter wave radar and the second millimeter wave radar can work synchronously. The synchronous work may include the first millimeter wave radar and the second millimeter wave radar following the same time reference when transmitting and receiving signals, and may also include the first millimeter wave radar and the second millimeter wave radar having the same transmission frequency, or transmitting and receiving signals according to a specific frequency difference, etc.

[0150] According to an embodiment of the present invention, the electronic device may include one or more processors, for example, processor 1, processor 2, etc. One or more computer programs may be executed by one or more processors in the electronic device to implement the steps of the pulse wave velocity determination method described above, for example, the first reference signal and the second reference signal may be analyzed, evaluated, and processed, and the target pulse wave velocity may be calculated. The electronic device may also store information such as reference classification results.

[0151] The electronic device can transmit and receive control signals and data information with the millimeter wave radar through the interface. The transmission and reception of control signals can, for example, control the first millimeter wave radar and the second millimeter wave radar to transmit and receive signals, and the transmission and reception of data information can, for example, receive and send reference classification results.

[0152] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining pulse wave velocity performed by an electronic device, comprising: Acquire a first reference signal for characterizing a vibration law of a first part of the measured object, wherein the first reference signal is obtained by processing a first original signal, and the first original signal includes a millimeter-wave radar echo signal reflected by the first part of the measured object; Acquire a second reference signal for characterizing a vibration law of a second part of the measured object, wherein the second reference signal is obtained by processing a second original signal, and the second original signal includes a millimeter-wave radar echo signal reflected by the second part of the measured object; Calculating the conduction time of the pulse wave from the first site to the second site based on the first reference signal and the second reference signal; calculating a conduction distance of the pulse wave from the first part to the second part; Based on the conduction time and the conduction distance, a target pulse wave velocity is calculated.

2. The method according to claim 1, wherein: The method further comprises: determining a reference pulse wave velocity corresponding to the first site and the second site; Based on the target pulse wave velocity and the reference pulse wave velocity, a reference classification result related to the measured object is generated.

3. The method according to claim 1, wherein: The first part includes: the heart part, or other predetermined parts other than the heart part; The second part includes: other predetermined parts except the heart part, and the first part is different from the second part; In the case where the first part includes a heart part, the calculating the conduction time of the pulse wave from the first part to the second part based on the first reference signal and the second reference signal includes: Performing differential processing on the first reference signal to generate a cardiac tremor signal; Based on the heartbeat cycle, dividing the heartbeat signal into a plurality of heartbeat signal segments; Based on the pulse wave cycle, dividing the second reference signal into a plurality of pulse wave signal segments, wherein the plurality of heart beat signal segments correspond one to one to the plurality of pulse wave signal segments; Based on the multiple cardiac pulsation signal segments and the multiple pulse wave signal segments, a conduction time of the pulse wave from the first site to the second site is calculated.

4. The method according to claim 3, wherein: The step of calculating the conduction time of the pulse wave from the first part to the second part based on the multiple cardiac pulsation signal segments and the multiple pulse wave signal segments comprises: For each of the cardiac pulsation signal segments, screening out an aortic valve opening signal point from each of the cardiac pulsation signal segments; For each of the cardiac pulsation signal segments, determining a first time corresponding to the aortic valve opening signal point; For each of the pulse wave signal segments, determining a pulse wave signal starting signal point corresponding to each of the pulse wave signal segments; For each of the pulse wave signal segments, determining a second time corresponding to a starting signal point of the pulse wave signal; Based on the first time and the second time, the conduction time of the pulse wave from the first site to the second site is calculated.

5. The method according to claim 4, wherein: The step of calculating the conduction time of the pulse wave from the first part to the second part based on the first moment and the second moment includes: Performing first outlier elimination processing on each of the first moments and each of the second moments respectively to obtain a first target moment and a second target moment; For each of the first target moments, calculating a first time difference between a second target time corresponding to the first target moment and the first target moment; The average value of each of the first time differences is calculated to obtain the conduction time of the pulse wave from the first part to the second part.

6. The method according to claim 3, wherein: In the case where the first part includes other predetermined parts except the heart part, the step of calculating the conduction time of the pulse wave from the first part to the second part based on the first reference signal and the second reference signal includes: Based on the pulse wave cycle, dividing the first reference signal into a plurality of first pulse wave signal segments, and dividing the second reference signal into a plurality of second pulse wave signal segments, wherein the plurality of first pulse wave signal segments correspond one to one to the plurality of second pulse wave signal segments; Determining a first starting signal point corresponding to each of the first pulse wave signal segments, and determining a second starting signal point corresponding to each of the second pulse wave signal segments; Determine a third time corresponding to the first start signal point, and a fourth time corresponding to the second start signal point; Based on the third time and the fourth time, the conduction time of the pulse wave from the first site to the second site is calculated.

7. The method according to claim 6, wherein: The calculating, based on the third moment and the fourth moment, the conduction time of the pulse wave from the first part to the second part comprises: Performing a second outlier elimination process on each of the third moments and each of the fourth moments respectively to obtain a third target moment and a fourth target moment; For each of the third target moments, calculating a second time difference between a fourth target time corresponding to the third target moment and the third target moment; The average value of each of the second time differences is calculated to obtain the conduction time of the pulse wave from the first part to the second part.

8. The method according to claim 1, wherein: The method further comprises: performing interference suppression processing on the first original signal and the second original signal respectively to eliminate the influence of the millimeter-wave radar echo signal reflected by other parts except the first part and the second part, so as to obtain a first candidate signal and a second candidate signal; Based on the transmission distance and transmission angle of the millimeter wave radar, a first range of interest is selected from the first part, and a second range of interest is selected from the second part; Determine a first preliminary selected signal corresponding to the first range of interest from the first candidate signals, and determine a second preliminary selected signal corresponding to the second range of interest from the second candidate signals; Based on a predetermined signal quality standard, the first reference signal is selected from the first preliminary selected signals, and the second reference signal is selected from the second preliminary selected signals.

9. The method according to claim 1, wherein: The calculating the conduction distance of the pulse wave from the first part to the second part comprises: determining a straight-line distance between the first portion and the second portion; Based on a predetermined correction coefficient and the straight-line distance, a conduction distance of the pulse wave from the first site to the second site is calculated.

10. A pulse wave velocity determination device, comprising: A first millimeter-wave radar, used to transmit a millimeter-wave radar signal to a first part of the object to be measured; A second millimeter-wave radar, used for transmitting a millimeter-wave radar signal to a second part of the measured object, wherein the first millimeter-wave radar is connected to the second millimeter-wave radar via a circuit; Electronic equipment, including: one or more processors; a memory for storing one or more computer programs, It is characterized in that the one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1 to 9.

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