A single sensor for detecting cardiopulmonary polyphasic oscillations

Abstract

The present application relates to a single sensor for detecting cardiopulmonary multi-frequency vibration, belonging to the technical field of medical devices, and relating to cardiopulmonary signal detection technology. The single sensor for detecting cardiopulmonary multi-frequency vibration is composed of a first transmission component, a piezoelectric film, a second transmission component and an absolute pressure sensor fixed layer stack, which synchronously and stably collects the mechanical vibration wave of the human chest wall, triggers the piezoelectric film to generate a piezoelectric signal that can reflect the human respiratory, ultra-low frequency heartbeat, heart shock and cardiopulmonary sound information, triggers the absolute pressure sensor to generate an absolute pressure signal reflecting the degree of adhesion of the chest wall to the sensor, and realizes the application effect of synchronously extracting the multi-frequency mechanical vibration information of the cardiopulmonary and the adhesion degree of the human body on the single sensor through a signal processing method, thereby providing an efficient and portable way to understand the cardiopulmonary activity and state.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and relates to the technical field of cardiopulmonary signal detection, in particular to a single sensor for detecting cardiopulmonary multi-frequency vibration. BACKGROUND

[0002] The movement of the heart and the lungs is inseparable. Cardiopulmonary disease is one of the important factors threatening people's life and health worldwide, and the trend of youth is increasingly prominent. Daily monitoring of the heart and lungs and early warning of diseases are key tasks in medicine, which puts new requirements on sensors for detecting the heart and lungs. Traditional sensing technologies include single detection of cardiopulmonary mechanical information such as heart sound, lung sound auscultation, respiratory wave (chest wall expansion and contraction caused by respiration), heart shock signal (SCG, local chest wall vibration caused by heartbeat), etc. The cardiopulmonary movement is a composite movement containing mechanical waves of different frequencies. However, the above single sensing technology can only reflect a certain frequency band of the cardiopulmonary movement. To fully reflect the mechanical wave movement of the heart and lungs, the signals of the above multiple sensors need to be collected. At the same time, the different degrees of adhesion of the sensor and the human chest wall will affect the effect of collecting the mechanical wave, changing the shape and quality of the signal waveform, and the current cardiopulmonary vibration monitoring technology does not integrate static pressure to reflect the adhesion of the sensor and the human chest wall. To fully reflect the mechanical activity information of the heart and lungs through the vibration waveform, static pressure needs to be extracted.

[0003] In the implementation process of the sensor, the wideband characteristics of the piezoelectric film show the potential to detect low-frequency to high-frequency mechanical vibration at the same time. This makes it possible to obtain the above multi-band cardiopulmonary vibration signals on a single sensor. The present application proposes a single sensor cardiopulmonary multi-band mechanical wave detection device based on a piezoelectric film, which can simultaneously extract respiratory waves, ultra-low frequency heart beat signals, heart shock signals and cardiopulmonary sound signals. To reflect the adhesion of the sensor and the human body, an absolute pressure sensor is used to collect the static pressure between the sensor and the human body as a quantitative adhesion. The present application provides an efficient and portable way to fully understand the mechanical vibration information of the heart and lungs and reflect the activity and state of the heart and lungs, and can be further applied to wearable and portable devices for the heart and lungs, providing the possibility for early detection and timely treatment of abnormal heart and lung, and helping to avoid the increase of medical costs and the waste of medical resources. SUMMARY

[0004] To solve the above problems, the present application provides a single sensor for detecting cardiopulmonary multi-frequency vibration, which synchronously collects piezoelectric signals and absolute pressure signals at the position of the heart and lung chest, and the piezoelectric signals can be further extracted as respiratory waves, ultra-low frequency heart beat signals, heart shock signals and cardiopulmonary sound signals, reflecting the mechanical vibration information of the heart and lungs in multiple frequency bands.

[0005] In one aspect, the embodiment of the present application provides a single sensor for detecting cardiopulmonary multi-frequency vibration, comprising a first transmission component, a piezoelectric film, a second transmission component and an absolute pressure sensor, which are sequentially stacked,

[0006] The first transmission component is used to transmit the vibration wave of the human chest cavity to the piezoelectric film.

[0007] The piezoelectric film is used to detect the analog piezoelectric signal caused by the pressure transmitted by the first transmission component.

[0008] The second transmission component is used to fix the piezoelectric film and the absolute pressure sensor as intermediate parts and transmit the pressure to the absolute pressure sensor.

[0009] The absolute pressure sensor is used to detect the analog absolute pressure signal caused by the pressure.

[0010] Based on the further improvement of the above-mentioned single sensor, the first transmission component is specifically:

[0011] It is made of soft insulating material suitable for contacting the human body and having good mechanical wave transmission ability.

[0012] It adopts a regular shape with parallel upper and lower surfaces, wherein the upper surface contacts the human body and the lower surface contacts the piezoelectric film.

[0013] The lower surface has the same shape as the piezoelectric film and the cross-sectional area is slightly smaller than that of the piezoelectric film.

[0014] Based on the further improvement of the above-mentioned single sensor, the lower surface of the first transmission component is aligned with the center of the piezoelectric film and the edges are fixed by adhesion.

[0015] Based on the further improvement of the above-mentioned single sensor, the second transmission component is specifically:

[0016] It is made of hard insulating material having good mechanical wave transmission ability.

[0017] It adopts a regular shape with parallel upper and lower surfaces, wherein the upper surface contacts the piezoelectric film and the lower surface contacts the absolute pressure sensor.

[0018] The upper surface has the same shape as the piezoelectric film and the cross-sectional area is slightly larger than that of the piezoelectric film.

[0019] The upper surface has a groove or a protrusion, wherein the cross-sectional shape of the groove or the protrusion of the upper surface is the same as that of the upper surface and the area is smaller than that of the piezoelectric film.

[0020] The lower surface is a groove or a plane and contacts the sensitive surface of the absolute pressure sensor.

[0021] Based on the further improvement of the above-mentioned single sensor, the second transmission component upper surface and the piezoelectric film contact fixed mode is that the piezoelectric film covers the upper surface groove or protrusion, and the edge is bonded and fixed.

[0022] Based on the further improvement of the above-mentioned single sensor, the second transmission component shape is regular shape or regular shape combination, wherein,

[0023] The regular shape is cylinder, cube, cuboid or polyhedron with two parallel surfaces;

[0024] The regular shape combination is that multiple regular shapes of the same kind or different kinds are fixed as a stable whole with axial center symmetry, edge alignment and surface contact.

[0025] Based on the further improvement of the above-mentioned single sensor, a fixed component is coupled and fixed with the second transmission component, and the absolute pressure sensor sensitive surface is slightly stressed with the second transmission component lower surface.

[0026] A single sensor heart-lung signal acquisition method for detecting heart-lung multi-frequency vibration, the method comprising:

[0027] Detecting human heart-lung signal by using the single sensor to obtain analog absolute pressure signal;

[0028] Obtaining static pressure value reflecting the degree of adhesion between human body and sensor by analog-to-digital conversion and filtering processing of analog absolute pressure signal;

[0029] Judging whether the static pressure value is in the preset interval, if not, adjusting the adhesion degree between the single sensor and human body according to the size of the static pressure value, and detecting human heart-lung signal by using the single sensor again until the static pressure value corresponding to the obtained analog absolute pressure signal is in the preset interval;

[0030] When the static pressure value is in the preset interval, obtaining the analog piezoelectric signal of the single sensor, and obtaining three-way synchronous ultra-low frequency heart signal, heart shock signal and heart-lung sound signal synchronously mapping heart vibration frequency by signal amplification, analog-to-digital conversion and signal decomposition of analog piezoelectric signal;

[0031] The preset interval refers to the pressure interval in which the adhesion state of human body and single sensor meets the effectiveness requirement of heart-lung signal.

[0032] A single sensor heart-lung signal acquisition method for detecting heart-lung multi-frequency vibration, the method comprising:

[0033] Detecting human heart-lung signal by using the single sensor to obtain analog absolute pressure signal and analog piezoelectric signal;

[0034] The analog absolute pressure signal is converted into a digital signal and filtered to obtain a static pressure value reflecting the degree of adhesion between the human body and the sensor, and the analog piezoelectric signal is amplified, converted into a digital signal, and decomposed to obtain three synchronized ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals that map the frequency of cardiac vibrations;

[0035] The three synchronized ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals obtained when the static pressure value is in a preset interval are used as effective heart-lung signals.

[0036] Based on the further improvement of any one of the above two methods, the three synchronized ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals that map the frequency of cardiac vibrations obtained by amplifying, converting into a digital signal, and decomposing the analog piezoelectric signal include:

[0037] The analog piezoelectric signal is amplified, converted into a digital signal, and decomposed into a digital piezoelectric signal;

[0038] The digital piezoelectric signal is decomposed into a respiratory wave, an ultra-low frequency cardiac signal, a heart shock signal, and a heart-lung sound signal;

[0039] The respiratory wave is peaked by a peak-seeking function to obtain the peak of the respiratory wave; the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal are truncated according to the peak position of the respiratory wave to obtain multiple segments of the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal;

[0040] For each segment, the peak of the ultra-low frequency cardiac signal is extracted by a peak-seeking algorithm, and the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal are each truncated according to the peak position to obtain multiple single-cycle ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals of different lengths;

[0041] Selecting segments of the single-cycle ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal that are the same as the number of cardiac vibrations, the period of each segment is used to calculate a period average as the period length of the equal-length segments of the single-cycle ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal;

[0042] The selected segments of the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal of different lengths are processed by a cubic spline interpolation method to obtain equal-length single-cycle signals of the corresponding ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal;

[0043] The equal-length single-cycle signals of the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal are time-domain averaged to obtain single-cycle signals of the synchronized ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal.

[0044] Compared with the prior art, the present application has the following advantages:

[0045] 1. Realize four frequency band cardiopulmonary mechanical waves collected on a single sensor, which can comprehensively reflect the mechanical vibration information of heart and lung.

[0046] 2. On the basis of multi-frequency band cardiopulmonary vibration detection, an absolute pressure sensor is added to collect static pressure signals, so as to reflect the adhesion degree of the sensor and the human body, and quantize the process, so that the detection of multi-frequency band mechanical waves is more accurate and efficient.

[0047] 3. The laminated structure can effectively transmit the vibration received by the piezoelectric film to the absolute pressure sensor below, and realize synchronous collection of signals.

[0048] 4. The deformation displacement design is added to the second transmission part, which effectively improves the collection sensitivity of the piezoelectric film and provides guarantee for the signal quality of multi-frequency band mechanical waves.

[0049] In the present application, the above technical solutions can be combined with each other to realize more preferred combination solutions. Other features and advantages of the present application will be described in the subsequent specification, and some advantages will become apparent from the specification, or will be understood by implementing the present application. The purpose and other advantages of the present application can be achieved and obtained from the contents specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0050] The accompanying drawings are included to provide a further understanding of the application and are incorporated herein and constitute a part of the application. The drawings illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0051] Figure 1 It is a structural schematic diagram of a single mechanical wave sensing module of an embodiment of the present application.

[0052] Figure 2 It is a system schematic diagram of a single sensor for detecting cardiopulmonary multi-frequency vibration in an embodiment of the present application.

[0053] Figure 3 It is a piezoelectric signal collected in an embodiment of the present application and extracted respiratory wave, ultra-low frequency heart signal, heart shock signal and cardiopulmonary sound signal.

[0054] Figure 4 It is an absolute pressure sensor signal collected in an embodiment of the present application and extracted static pressure value. DETAILED DESCRIPTION

[0055] The preferred embodiments of the present application will be specifically described below in combination with the drawings, wherein the drawings constitute a part of the present application and are used to illustrate the principles of the embodiments of the present application, but are not used to limit the scope of the present application.

[0056] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0058] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the invention.

[0059] Example 1

[0060] like Figure 1 As shown, this embodiment discloses a single sensor for detecting cardiopulmonary multi-frequency vibrations, comprising a first transmission component, a piezoelectric film, a second transmission component, and an absolute pressure sensor stacked sequentially.

[0061] The first transmission component is used to transmit the vibration waves of the human chest cavity to the piezoelectric film;

[0062] A piezoelectric thin film is used to detect the analog piezoelectric signal generated by the pressure transmitted from the first transmission component;

[0063] The second transmission component serves as an intermediate part to fix the piezoelectric film and the absolute pressure sensor, and transmits the pressure to the absolute pressure sensor.

[0064] An absolute pressure sensor is used to detect an analog absolute pressure signal generated by the pressure.

[0065] Furthermore, the first transmission component specifically comprises:

[0066] It is made of a soft insulating material that is suitable for contact with the human body and has good mechanical wave conduction ability;

[0067] It adopts a regular shape with parallel upper and lower surfaces, where the upper surface contacts the human body and the lower surface contacts the piezoelectric film;

[0068] The lower surface has the same shape as the piezoelectric film, but its cross-sectional area is slightly smaller than that of the piezoelectric film.

[0069] Furthermore, the lower surface of the first transmission component is aligned with the piezoelectric film at the center and the edges are bonded and fixed.

[0070] Specifically, the first transmission component adopts a regular shape with parallel upper and lower surfaces, preferably a cylinder, a square, a cuboid, an elliptical cylinder or a polygon, wherein the two parallel surfaces can be of the same shape or different shapes, but for the purpose of wearing comfort, the surface in contact with the human body is preferably of a non-angled shape, such as a circle, an ellipse or a polygon with rounded corners; for the purpose of fixing the piezoelectric film, the other surface must be consistent with the shape of the piezoelectric film and slightly smaller in cross-sectional area than the piezoelectric film, so that the edges of the piezoelectric film are bonded and fixed to the edges of the contact surface of the first transmission component.

[0071] Preferably, the first transmission component is in the shape of a cylinder, a cuboid or a square, slightly smaller in cross-sectional area than the piezoelectric film, and made of elastic ethylene-vinyl acetate copolymer (EVA), thermoplastic elastomer (TPE), polyurethane (PU) or silicone rubber, which can effectively transmit the vibration of the human chest wall to the underlying piezoelectric film.

[0072] Preferably, between the first transmission component and the underlying piezoelectric film, a solid glue, double-sided tape, hot melt glue, sealant or soluble adhesive is used for pasting, which plays a stabilizing role.

[0073] Preferably, the piezoelectric film is in the shape of a square, a rectangle or a circle, and is made of polyvinylidene fluoride (PVDF), vinylidene fluoride-maleic acid copolymer (VDF-TrFE), lead zirconate titanate (PZT) or aluminum zirconium oxide (ZAO).

[0074] Further, the second transmission component is specifically:

[0075] Made of a hard insulating material with good mechanical wave conduction ability;

[0076] Adopts a regular shape with parallel upper and lower surfaces, wherein the upper surface is in contact with the piezoelectric film and the lower surface is in contact with the absolute pressure sensor;

[0077] The upper surface is of the same shape as the piezoelectric film and slightly larger in cross-sectional area than the piezoelectric film;

[0078] The upper surface has a groove or a protrusion, wherein the cross-sectional shape of the groove or protrusion on the upper surface is the same as that of the upper surface and the area is smaller than that of the piezoelectric film;

[0079] The lower surface is a groove or a flat surface in contact with the sensitive surface of the absolute pressure sensor.

[0080] Specifically, the upper surface of the second transmission component is fixed with the piezoelectric film, and the piezoelectric film is fixed with the first transmission component, so that the three constitute a stable whole. The upper surface needs to be the same shape as the piezoelectric film, and the area is slightly larger than the piezoelectric film, and the two can be fixed by edge bonding. The surface of the second transmission component in contact with the piezoelectric film is designed with grooves or protrusions to increase the deformation displacement of the piezoelectric film. When the human body vibration wave is conducted through the first transmission component, the grooves or protrusions smaller than the area of the piezoelectric film make the gap between the piezoelectric film and the second transmission component cause the vibration of the surface of the piezoelectric film, so that the piezoelectric film is more likely to generate a piezoelectric signal, and the detection of the vibration signal is more sensitive.

[0081] Specifically, the lower surface of the second transmission component needs to be in contact with the absolute pressure sensor, and the two need to be coupled and fixed as a whole. The shape design of the lower surface is related to the absolute pressure sensor. According to the shape and type of the absolute pressure sensor, the lower surface can be designed as a groove or a flat surface. Preferably, the lower surface is designed as a groove, which can accommodate the sensitive surface of the absolute pressure sensor and form a fixed structure together, and the inner surface of the groove needs to be in direct contact with the sensitive surface of the absolute pressure sensor. At the same time, the shape of the sensitive surface of the absolute pressure sensor may be different from that of the piezoelectric film. For example, the piezoelectric film is circular, and the sensitive surface of the absolute pressure sensor is square. Therefore, the upper and lower surfaces of the second transmission component may be designed in different shapes, but need to be symmetrical around the central axis to ensure stable conduction of the vibration wave. In addition, the second transmission component can be a separate component or a combination of two components, for example: a cylinder and a cube form a whole, the upper surface of the cylinder is fixed with the piezoelectric film, and the lower surface of the cube is coupled and fixed with the absolute pressure sensor, or a combination of two or more identical components. It should be noted that the above is only one example of the technical point in the present application.

[0082] Preferably, the second transmission component and the absolute pressure sensor are fixed by contact coupling. The edge is fixed by magic tape, buckle, screw, or a shell that can accommodate both and form a fixed structure.

[0083] Further, the upper surface of the second transmission component is fixed with the piezoelectric film by covering the grooves or protrusions on the upper surface with the piezoelectric film and bonding the edges.

[0084] Preferably, the upper surface of the second transmission component and the piezoelectric film are pasted by using solid glue, double-sided tape, hot melt glue, sealant or soluble adhesive.

[0085] Preferably, the lower surface is a groove or a flat surface for contact coupling with the sensitive surface of the absolute pressure sensor. Figure 1The lower surface of the embodiment is a groove that just covers the absolute pressure sensor, and the bottom surface of the lower surface contacts the sensitive surface of the absolute pressure sensor.

[0086] According to the piezoelectric film characteristics, when the surface is deformed, the vibration generated by the drum surface effect can make the piezoelectric film better generate an analog piezoelectric signal. Whether the upper surface of the second transmission component is a groove or a protrusion, as long as it can form a cavity with the piezoelectric film, receive the human body vibration conducted by the first transmission component, and drive the piezoelectric film at the cavity position to vibrate.

[0087] Further, the second transmission component is in the shape of a regular shape or a combination of regular shapes, wherein,

[0088] The regular shape is a cylinder, a cube, a cuboid, or a polygon with two parallel surfaces;

[0089] The combination of regular shapes is a plurality of regular shapes of the same type or different types fixed as a stable whole in axial center symmetry, edge alignment, and surface contact.

[0090] Further, the fixed component is coupled and fixed with the second transmission component, and the sensitive surface of the absolute pressure sensor is in slight force or no force contact with the lower surface of the second transmission component.

[0091] Preferably, the external shape of the second transmission component is a cuboid, a cylinder, or a cube, and the preferred material is 3D printing material such as polylactic acid (PLA), acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene terephthalate (PETG), thermoplastic polyurethane (TPU), or nylon.

[0092] Preferably, the absolute pressure sensor is a strain, piezoresistive, or capacitive sensor that can extract static pressure information to quantify the fit between the sensor and the chest wall.

[0093] Further, the fixed component is coupled and fixed with the second transmission component, and the sensitive surface of the absolute pressure sensor is in slight force or no force contact with the lower surface of the second transmission component.

[0094] Preferably, the fixed component is in the shape of a rectangle, a square, or a circle, and is made of a PCB board, a metal plate, or a plastic plate.

[0095] Preferably, the connection between the absolute pressure sensor and the fixed component is by welding or solid glue, double-sided tape, hot melt glue, sealant, or soluble adhesive, which plays a stabilizing role.

[0096] Embodiment 2

[0097] Another embodiment of the present application discloses a single-sensor cardiopulmonary signal acquisition method for detecting cardiopulmonary multi-frequency vibration, the method comprising:

[0098] The single sensor is used to detect the cardiopulmonary signal of the human body to obtain an analog absolute pressure signal.

[0099] The analog absolute pressure signal is subjected to analog-digital conversion and filtering processing to obtain a static pressure value reflecting the degree of adhesion between the human body and the sensor.

[0100] It is judged whether the static pressure value is within a preset interval, if not, the adhesion degree between the single sensor and the human body is adjusted according to the size of the static pressure value, and the single sensor is used again to detect the cardiopulmonary signal of the human body until the static pressure value corresponding to the obtained analog absolute pressure signal is within the preset interval.

[0101] When the static pressure value is within the preset interval, the analog piezoelectric signal of the single sensor is obtained, and the analog piezoelectric signal is subjected to signal amplification, analog-digital conversion and signal decomposition to obtain three-way synchronous ultralow-frequency heart signal, heart vibration signal and cardiopulmonary sound signal signals synchronously mapping the frequency of cardiac vibration.

[0102] The preset interval refers to a pressure interval in which the adhesion state between the human body and the single sensor meets the effectiveness requirement of the cardiopulmonary signal.

[0103] Specifically, in the embodiment, the sensor collects the mechanical vibration wave generated by the human body, wherein the piezoelectric film generates an analog piezoelectric signal based on the collected mechanical vibration wave, and the absolute pressure sensor generates an analog absolute pressure signal based on the collected mechanical vibration wave. Specifically, the obtained continuous static pressure signal is calculated to obtain an average pressure signal as the static pressure signal value in this state:

[0104]

[0105] Wherein, P represents the static pressure signal in this state, P i is the continuous static pressure signal collected.

[0106] According to the pressure signal-pressure value relationship curve in the official test data document of the absolute pressure sensor, the pressure value (N) under this signal can be determined:

[0107] N=f(P)

[0108] N is the static pressure value in this state, and f is the pressure signal-pressure value relationship function of the absolute pressure sensor, which is determined by the specific sensing principle of the absolute pressure sensor.

[0109] According to the pressure value, the adhesion degree of the chest wall can be divided into different grades by setting a threshold value.

[0110] Specifically, in the embodiment, the pressure range of 1-2N is selected as a suitable pressure interval, and the fitting degree in the pressure interval less than 1N is determined as not normal fitting, and the fitting degree in the pressure interval greater than 2N is determined as too tight fitting:

[0111]

[0112] Degree represents the fitting degree of the sensor and the chest wall in this state, S represents that the fitting degree is not tight enough, A represents that the fitting degree is suitable, and L represents that the fitting degree is too tight.

[0113] Further, the three-way synchronized ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals obtained by signal amplification, analog-digital conversion and signal decomposition of the analog piezoelectric signals, comprise:

[0114] The analog piezoelectric signals are subjected to signal amplification and analog-digital conversion to obtain digital piezoelectric signals;

[0115] The digital piezoelectric signals are decomposed into respiratory waves, ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals;

[0116] The respiratory waves are subjected to peak searching by a peak searching function to obtain wave peaks of the respiratory waves, and the ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals are cut off according to the positions of the wave peaks of the respiratory waves to obtain multiple segments of the ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals;

[0117] For each segment, the wave peaks of the ultra-low frequency heart beat signals are extracted by a peak searching algorithm, and the ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals are cut off according to the positions of the wave peaks to obtain multiple single-cycle ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals with different lengths;

[0118] The segments of the single-cycle ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals with the same number of heart beats are selected, and the cycle average values of the above segments are taken as the cycle lengths of the equal-length segments of the single-cycle ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals;

[0119] The selected segments of the ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals with different lengths are processed by a cubic spline interpolation method to obtain equal-length single-cycle signals of the corresponding ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals;

[0120] The equal-length single-cycle signals of the ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals are subjected to time domain averaging to obtain single-cycle signals of the synchronized ultra-low frequency heart beat signals, heart shock signals and heart-lung sound signals.

[0121] Specifically, for a length of breath wave, the peak BT of the breath wave is extracted by a peak search function i , i = 1, 2, 3,.... n, n is the number of breath waves. Because the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal are related to the cardiac vibration cycle, the segments of the ultra-low frequency cardiac signal ULF_SCG i , the heart shock signal SCG i , and the heart-lung sound signal PCG i can be obtained by peak truncation.

[0122] For each segment of the signal, the peak value US-P j of the cardiac vibration signal is extracted by a peak search algorithm, j = 1, 2, 3,.... m, m is the number of cardiac vibration waves, and each segment of the ultra-low frequency cardiac vibration signal ULF_SCG i , the heart shock signal SCG j , and the heart-lung sound signal PCG j is truncated according to the peak value to form a plurality of single-cycle segments with different lengths, m single-cycle segments are selected from the plurality of single-cycle segments, and the cycle average value of the m single-cycle segments is used as the cycle length T of the equal-length segment:

[0123]

[0124] wherein T j is the cycle of each unequal-length segment.

[0125] The unequal-length signals are processed by a cubic spline interpolation method to obtain equal-length multi-cycle signals:

[0126] x SCG_j = f spline (SCG j , T)

[0127] x PCG_j = f spline (PCG j , T)

[0128] x ULF_SCG_j = f spline (ULF_SCG j , T)

[0129] wherein x SCG_j , x PCG_j , and x ULF_SCG_j are equal-length single-cycle signal segments of the heart shock signal, the heart-lung sound signal, and the ultra-low frequency cardiac vibration signal, respectively.

[0130] The equal-length multi-cycle signals after processing are respectively subjected to time domain averaging to obtain single-cycle signals of the synchronized heart shock signal, the heart-lung sound signal, and the ultra-low frequency cardiac vibration signal:

[0131]

[0132]

[0133]

[0134] wherein, x SCG_ave , x PCG_ave , x ULF_SCG_ave are single period signals corresponding to synchronous heart sound signals, cardiopulmonary sound signals, and ultra-low frequency heart vibration signals, respectively, with a period of T.

[0135] Specifically, the preset interval is based on the actual human body collection of the single sensor, and the piezoelectric signal collected is subjected to signal extraction to obtain three signals of low frequency to high frequency, ULF-SCG, SCG, and PCG signals. The SCG signal based on the standard accelerometer and the PCG signal based on the microphone are collected, and the collected SCG signal of the piezoelectric and the SCG signal of the accelerometer and the PCG signal of the piezoelectric and the PCG signal of the microphone are subjected to the following correlation analysis:

[0136] Five continuous waveforms are selected for pairwise correlation analysis, which is performed by using the Pearson correlation coefficient method. When the Pearson correlation coefficients all reach 95%, it is determined that the cardiopulmonary signal is effective and meets the requirements. The static pressure value at this time is taken as a reference, and the reference and above are taken as the preset interval. The ULF-SCG signal does not need to be subjected to correlation analysis because it has no standard signal. In addition, it is the most difficult signal to be disturbed. As long as the SCG and PCG signals meet the requirements, the ULF-SCG signal will also meet the requirements.

[0137] In actual application, the preset interval is a factory preset value establishment method provided before use in the embodiment. Those skilled in the art should understand that the method for obtaining the preset interval should not be limited to the above description, but can also be measured by other automatic methods such as simulation and calculation.

[0138] When the static pressure value measured by the above method is not within the threshold interval range, the system does not collect and process the piezoelectric signal into a multi-frequency cardiopulmonary signal until the sensor is adjusted to a suitable degree of adhesion to the human body, and the static pressure value is within the suitable interval range. The system will start collecting and processing the piezoelectric signal to decompose into a multi-frequency cardiopulmonary signal. The purpose of this is to first determine that the sensor is suitably adhered to the human body through the detection of the static pressure value, thereby ensuring that the piezoelectric signal collected and the multi-frequency cardiopulmonary signal obtained by further decomposition are all good and usable signals, and reducing the energy consumption of the system for collecting and processing invalid data.

[0139] Embodiment 3

[0140] Another embodiment of the present application discloses another single-sensor method for detecting cardiopulmonary multi-frequency vibration, which comprises the following steps:

[0141] The single sensor is used to detect the cardiopulmonary signals of the human body to obtain an analog absolute pressure signal and an analog piezoelectric signal;

[0142] The analog absolute pressure signal is subjected to analog-digital conversion and filtering to obtain a static pressure value reflecting the adhesion degree of the human body to the sensor, and the analog piezoelectric signal is subjected to signal amplification, analog-digital conversion and signal decomposition to obtain three-way synchronous ultralow-frequency heart motion signals, heart shock signals and cardiopulmonary sound signals synchronously mapping the heart vibration frequency;

[0143] The three-way synchronous ultralow-frequency heart motion signals, heart shock signals and cardiopulmonary sound signals obtained when the static pressure value is in a preset interval are taken as effective cardiopulmonary signals.

[0144] In the embodiment, the processing algorithm of the static pressure value and the processing algorithm of the piezoelectric signal are consistent with those of Embodiment 2, and the difference lies in that, in the embodiment, the piezoelectric signal is continuously collected and processed regardless of whether the static pressure value is in the suitable interval, and the piezoelectric signal with the static pressure value in the suitable interval is preferably extracted or highlighted, and the decomposed multi-frequency cardiopulmonary signals are processed, and all the signal data during the period when the patient wears the sensor are collected and saved. Although the processing may increase the system energy consumption and processing load, the complete data retained can be used for subsequent analysis and technical improvement.

[0145] The above two embodiments provide two different choices for the system application of the present application, and the person skilled in the art can select the implementation according to the specific scene and needs.

[0146] Embodiment 4

[0147] A fourth embodiment of the present application, as shown in Figure 2 discloses a single-sensor cardiopulmonary signal acquisition system for detecting cardiopulmonary multi-frequency vibration, which comprises a single-sensor module for detecting cardiopulmonary multi-frequency vibration, a signal receiving circuit module, a multi-frequency signal extraction module and a signal amplification module, wherein:

[0148] The single-sensor module is used to synchronously collect piezoelectric signals and absolute pressure signals at the cardiopulmonary thoracic cavity position, and the structure is the same as that of Embodiment 1;

[0149] The signal receiving circuit module is used to amplify and analog-digital convert the piezoelectric signals and absolute pressure signals collected by the single mechanical wave sensing module to obtain digital piezoelectric signals and digital absolute pressure signals;

[0150] The multi-band signal extraction module comprises a signal decomposition module and a signal filtering module, wherein the signal decomposition module is configured to decompose the digital piezoelectric signal to obtain a respiratory wave, an ultra-low frequency heart beat signal, a heart shock signal and a heart-lung sound signal, and the signal filtering module is configured to filter the digital absolute pressure value signal to obtain a static pressure value.

[0151] The signal processing method in the multi-band signal extraction module and the signal receiving circuit in the system is the same as that in Embodiment 2, and will not be described again.

[0152] Those skilled in the art can understand that all or part of the processes of the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the program can be stored in a computer readable storage medium. The computer readable storage medium is a disk, an optical disk, a read-only memory or a random access memory, etc.

[0153] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A single sensor for detecting cardiopulmonary polyphasic oscillations, characterized in that, The first transmission component, the piezoelectric film, the second transmission component, and the absolute pressure sensor are sequentially stacked. The first transmission component is used to transmit the vibration wave of the human chest cavity to the piezoelectric film. The piezoelectric film is used to detect the analog piezoelectric signal generated by the pressure transmitted by the first transmission component. The second transmission component is used to fix the piezoelectric film and the absolute pressure sensor as intermediate parts and transmit the pressure to the absolute pressure sensor. The absolute pressure sensor is used to detect the analog absolute pressure signal generated by the pressure. The analog piezoelectric signal is amplified, converted into a digital signal, and decomposed to obtain three synchronized ultra-low frequency cardiac signals, including a heart vibration frequency signal, a heart shock signal, and a heart-lung sound signal. The analog piezoelectric signal is amplified, converted into a digital signal, and decomposed to obtain three synchronized ultra-low frequency cardiac signals, including a heart vibration frequency signal, a heart shock signal, and a heart-lung sound signal. The peak of the respiratory wave is obtained by a peak search function, and the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal are truncated according to the peak position of the respiratory wave to obtain multiple segments of the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal. For each segment, the peak of the ultra-low frequency cardiac signal is extracted by a peak search algorithm, and the ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal are truncated according to the peak position to obtain multiple single-cycle ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals with different lengths. The same number of single-cycle ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals as the number of heart vibrations are selected, and the cycle average of each segment is calculated as the cycle length of the equal-length segment of the single-cycle ultra-low frequency cardiac signal, the heart shock signal, and the heart-lung sound signal. The selected ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals with different lengths are processed by a cubic spline interpolation method to obtain equal-length single-cycle signals of the corresponding ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals. The equal-length single-cycle signals of the ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals are time-domain averaged to obtain single-cycle signals of the synchronized ultra-low frequency cardiac signals, heart shock signals, and heart-lung sound signals. The first transmission component is made of a soft insulating material suitable for contacting the human body and having good mechanical wave conduction ability.

2. The single sensor for detecting cardiorespiratory multifrequency vibrations of claim 1, wherein, The first transmission component has a regular shape with parallel upper and lower surfaces, wherein the upper surface contacts the human body and the lower surface contacts the piezoelectric film. The lower surface of the first transmission component has the same shape as the piezoelectric film, and the cross-sectional area is slightly smaller than that of the piezoelectric film. The lower surface of the first transmission component is aligned with the center of the piezoelectric film, and the edges are bonded and fixed. The second transmission component is made of a hard insulating material with good mechanical wave conduction ability.

3. The single sensor for detecting cardiorespiratory multifrequency vibrations of claim 2, wherein, The second transmission component has a regular shape with parallel upper and lower surfaces, wherein the upper surface contacts the piezoelectric film and the lower surface contacts the absolute pressure sensor.

4. The single sensor for detecting cardiorespiratory multifrequency vibrations of claim 3, wherein, The upper surface of the second transmission component has the same shape as the piezoelectric film, and the cross-sectional area is slightly larger than that of the piezoelectric film. The upper surface of the second transmission component has a groove or a protrusion, wherein the cross-sectional shape of the groove or the protrusion is the same as that of the upper surface, and the area is smaller than that of the piezoelectric film. ​ ​ ​ The lower surface is a groove or a plane, and is in contact with the sensitive surface of the absolute pressure sensor.

5. The single sensor for detecting cardio-respiratory multi-frequency vibrations of claim 4, wherein, The upper surface of the second transmission component is in contact with the piezoelectric film in a fixed manner, i.e., the piezoelectric film covers the groove or protrusion on the upper surface and is fixed by edge bonding.

6. The single sensor for detecting cardio-respiratory multi-frequency vibrations of claim 5, wherein, The second transmission component has a regular shape or a combination of regular shapes, wherein, The regular shape is a cylinder, a cube or a cuboid. The combination of regular shapes is a plurality of regular shapes of the same kind or different kinds, which are fixed as a stable whole in a manner of axial center symmetry, edge alignment and surface contact.

7. The single sensor for detecting cardio-respiratory multi-frequency vibrations of claim 6, wherein, The method comprises:

8. The single-sensor cardiopulmonary signal acquisition method for detecting cardiopulmonary multi-frequency oscillations according to any one of claims 1 to 7, characterized in that, detecting the cardiopulmonary signal of the human body by using the single sensor to obtain an analog absolute pressure signal; performing analog-digital conversion and filtering processing on the analog absolute pressure signal to obtain a static pressure value reflecting the adhesion degree of the human body to the sensor; determining whether the static pressure value is within a preset interval, and if not, adjusting the adhesion degree between the single sensor and the human body according to the size of the static pressure value, and detecting the cardiopulmonary signal of the human body by using the single sensor again until the static pressure value corresponding to the obtained analog absolute pressure signal is within the preset interval; when the static pressure value is within the preset interval, obtaining an analog piezoelectric signal of the single sensor, and performing signal amplification, analog-digital conversion and signal decomposition on the analog piezoelectric signal to obtain three synchronous ultralow frequency heart beat signals, heart shock signals and cardiopulmonary sound signals synchronously mapping the frequency of heart vibration; The preset interval refers to a pressure interval in which the adhesion state of the human body to the single sensor meets the effectiveness requirement of the cardiopulmonary signal. The method comprises:

9. The single-sensor cardiopulmonary signal acquisition method for detecting cardiopulmonary multi-frequency oscillations according to any one of claims 1 to 7, characterized in that, detecting the cardiopulmonary signal of the human body by using the single sensor to obtain an analog absolute pressure signal and an analog piezoelectric signal; performing analog-digital conversion and filtering processing on the analog absolute pressure signal to obtain a static pressure value reflecting the adhesion degree of the human body to the sensor, and performing signal amplification, analog-digital conversion and signal decomposition on the analog piezoelectric signal to obtain three synchronous ultralow frequency heart beat signals, heart shock signals and cardiopulmonary sound signals synchronously mapping the frequency of heart vibration; the three synchronous ultralow frequency heart beat signals, heart shock signals and cardiopulmonary sound signals obtained when the static pressure value is within the preset interval are used as effective cardiopulmonary signals. ​

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