Vital signs evaluation system based on data analysis

Abstract

The present application discloses a vital sign evaluation system based on data analysis, which relates to the field of vital sign monitoring technology. The specific scheme includes: mixing the echo signals from the target area to obtain two intermediate frequency signals, and then amplifying them to obtain the first signal and the second signal; then performing respiratory filtering and heartbeat filtering to obtain the third signal and the fourth signal, and then determining the respiratory frequency and the heartbeat frequency, and then updating the respiratory filter parameters and the heartbeat filter parameters; obtaining the respiratory frequency and the heartbeat frequency at the current moment, as well as multiple historical respiratory frequencies and multiple historical heartbeat frequencies, determining the heart rate variability and respiratory depth changes corresponding to the current moment, and then determining the vital sign evaluation results based on the vital sign evaluation score formula. The present disclosure can solve the problem in the prior art that the filtering processing cannot follow the frequency changes of the vital sign signal in real time, resulting in inaccurate vital sign data, and improve the accuracy of the vital sign evaluation results.

Description

Technical Field

[0001] The present application relates to the technical field of vital sign monitoring, and in particular to a vital sign evaluation system based on data analysis. Background Art

[0002] Contactless collection of vital sign data (such as respiratory rate and heart rate) involves processing the echo signals reflected from the human body. Because the frequency range of vital sign signals is relatively narrow, filtering is required in noisy environments. Once acquired, the vital sign data needs to be analyzed and processed to produce a vital sign evaluation result.

[0003] However, the existing filtering processing cannot follow the frequency changes of vital sign signals in real time, resulting in inaccurate vital sign data, which leads to poor accuracy of vital sign evaluation results and little reference value of the evaluation results. Summary of the Invention

[0004] The embodiments of the present application provide a vital sign evaluation system based on data analysis, which solves the problem in the prior art that filtering processing cannot follow the frequency changes of vital sign signals in real time, resulting in inaccurate vital sign data, and improves the accuracy of vital sign evaluation results.

[0005] In a first aspect, an embodiment of the present application provides a method for evaluating vital signs based on data analysis, comprising:

[0006] Acquire the echo signal from the target area, perform mixing processing on the echo signal, and obtain two intermediate frequency signals, wherein the target area is the area where the human body is located, and the echo signal is the reflection signal of the radar signal emitted to the target area; perform intermediate frequency amplification processing on the two intermediate frequency signals to obtain a first signal and a second signal; perform respiratory filtering processing and heartbeat filtering processing according to the first signal and the second signal, respectively, to obtain a third signal and a fourth signal, respectively, wherein the first filtering parameter of the respiratory filtering processing is different from the second filtering parameter of the heartbeat filtering processing, and the first filtering parameter and the second filtering parameter both include corresponding filter control voltage and filter bandwidth; determine the respiratory frequency and the heart rate according to the third signal and the fourth signal respectively, and store them in the vital signs database; update the first signal and the fourth signal respectively according to the respiratory frequency and the heart rate. Filter parameters, second filter parameters; obtain the respiratory frequency at the current moment, multiple first historical respiratory frequencies within a first preset time period before the current moment, and the heart rate at the current moment, multiple first historical heart rates within a first preset time period before the current moment from the vital signs database, and determine the heart rate variability corresponding to the current moment and the change in breathing depth corresponding to the current moment according to the respiratory frequency at the current moment, multiple first historical respiratory frequencies, the heart rate at the current moment, and multiple first historical heart rates; determine the vital signs evaluation score based on the vital signs evaluation score formula according to the respiratory frequency at the current moment, the heart rate variability corresponding to the current moment, and the change in breathing depth corresponding to the current moment; determine the vital signs evaluation result according to the vital signs evaluation score and the preset evaluation threshold.

[0007] Furthermore, the first filter parameter and the second filter parameter are updated according to the respiratory rate and the heart rate respectively, including:

[0008] The filter control voltage corresponding to the first filter parameter and the filter control voltage corresponding to the second filter parameter are updated based on the control voltage adjustment formula according to the respiratory frequency and the heart rate respectively; the filter bandwidth corresponding to the first filter parameter and the filter bandwidth corresponding to the second filter parameter are updated based on the bandwidth adjustment formula according to the power of the third signal corresponding to the respiratory frequency and the power of the fourth signal corresponding to the heart rate respectively.

[0009] The control voltage adjustment formula is shown in formula (1):

[0010] (1)

[0011] In formula (1), represents the filter control voltage, represents the proportional gain coefficient, Indicates respiratory rate or heart rate, represents the filter center frequency corresponding to the respiratory rate or heart rate, represents the integral gain coefficient, Indicates the length of the integration time window, represents the integration variable.

[0012] The bandwidth adjustment formula is shown in formula (2):

[0013] (2)

[0014] In formula (3), represents the filter bandwidth, represents the minimum bandwidth of the filter, represents the instantaneous adjustment coefficient, Indicates taking the maximum value, represents the power of the third signal corresponding to the respiratory frequency or the power of the fourth signal corresponding to the heart rate, Indicates the preset power threshold, Indicates the preset dead zone width.

[0015] Furthermore, according to the current respiratory rate, the current heart rate, the heart rate variability corresponding to the current moment, and the change in breathing depth corresponding to the current moment, a vital sign evaluation score is determined based on the vital sign evaluation score formula, including:

[0016] According to the current respiratory rate, based on the respiratory evaluation score formula, the respiratory evaluation score is determined; according to the current heart rate, based on the heartbeat evaluation score formula, the heartbeat evaluation score is determined; according to the heart rate variability corresponding to the current moment, the heart rate variability evaluation score is determined; according to the corresponding respiratory depth change at the current moment, the respiratory depth change evaluation score is determined; according to the respiratory evaluation score, heartbeat evaluation score, heart rate variability evaluation score, and respiratory depth change evaluation score, based on the vital signs evaluation score formula, the vital signs evaluation score is determined.

[0017] The breathing evaluation score formula is shown in formula (3):

[0018] (3)

[0019] In formula (3), represents the respiratory evaluation score, Represents the respiratory rate, represents the optimal respiratory rate, Indicates taking the maximum value, Indicates tachypnea rate, Indicates bradypnea rate.

[0020] The heartbeat evaluation score formula is shown in formula (4):

[0021] (4)

[0022] In formula (4), Indicates the heartbeat evaluation score, Indicates the heart rate, Indicates the optimal heart rate, Indicates taking the maximum value, Indicates the heart rate. Indicates a slow heartbeat rate.

[0023] Furthermore, determining the respiratory rate and the heart rate according to the third signal and the fourth signal respectively includes:

[0024] The frequency determination step is performed on the third signal and the fourth signal respectively to obtain the respiratory frequency and the heart rate; the frequency determination step includes: determining multiple observation samples based on the third signal or the fourth signal; determining an autocorrelation matrix based on the multiple observation samples; performing eigenvalue decomposition on the autocorrelation matrix to obtain multiple noise subspace basis vectors; constructing a target spectrum based on the multiple noise subspace basis vectors; performing peak search on the target spectrum, and determining the frequency corresponding to the peak as the respiratory frequency or the heart rate.

[0025] Furthermore, the target spectrum is a MUSIC spectrum, and the target spectrum is constructed according to multiple noise subspace basis vectors, including:

[0026] According to multiple noise subspace basis vectors and the target spectrum determination formula, a MUSIC spectrum is constructed.

[0027] The target spectrum determination formula is shown in formula (5):

[0028] (5)

[0029] In formula (5), Indicates the frequency The signal strength at represents the order of the autocorrelation matrix, represents the number of observation samples, Indicates frequency The corresponding direction vector, Represents the noise subspace matrix corresponding to multiple noise subspace basis vectors, express The index number of the column vector in .

[0030] Furthermore, the vital signs evaluation score formula is shown in formula (6):

[0031] (6)

[0032] In formula (6), represents the vital signs assessment score, represents the respiratory evaluation score, Indicates the heartbeat evaluation score, represents the heart rate variability evaluation score, Indicates the breathing depth change evaluation score, 、 、 、 They represent the weight of the respiration evaluation score, the weight of the heartbeat evaluation score, the weight of the heart rate variability evaluation score, and the weight of the breathing depth change evaluation score respectively.

[0033] Furthermore, the method further comprises:

[0034] According to multiple historical breathing evaluation scores, multiple historical heartbeat evaluation scores, multiple historical heart rate variability evaluation scores, and multiple historical breathing depth change evaluation scores within the second preset time period before the current moment, the weight of the breathing evaluation score, the weight of the heartbeat evaluation score, the weight of the heart rate variability evaluation score, and the weight of the breathing depth change evaluation score are updated respectively.

[0035] In a second aspect, an embodiment of the present application provides a vital sign evaluation system based on data analysis, comprising:

[0036] Front-end radar module, intermediate frequency processing module, control processing module, vital sign evaluation module, the intermediate frequency processing module includes a front-end circuit module, a first adaptive filtering module, and a second adaptive filtering module; the front-end radar module is used to transmit radar signals to the target area, and receive echo signals from the target area, perform frequency mixing on the echo signals, obtain two intermediate frequency signals, and send them to the front-end circuit module; wherein, the target area is the area where the human body is located, and the echo signal is the reflected signal of the radar signal transmitted to the target area; the front-end circuit module is used to perform intermediate frequency amplification processing on the two intermediate frequency signals to obtain a first signal and a second signal; the first adaptive filtering module is used to perform respiratory filtering processing based on the first signal and the second signal to obtain a third signal; the second adaptive filtering module is used to perform heartbeat filtering processing based on the first signal and the second signal to obtain a fourth signal; wherein, the first filtering parameter of the respiratory filtering processing is different from the second filtering parameter of the heartbeat filtering processing, and the first filtering parameter and the second filtering parameter both include the corresponding filter control voltage, filter bandwidth ; A control processing module is used to determine the respiratory rate and heart rate according to the third signal and the fourth signal respectively, and store them in the vital signs database; it is also used to update the first filter parameter and the second filter parameter according to the respiratory rate and the heart rate respectively; a vital signs evaluation module is used to obtain the respiratory rate at the current moment, multiple first historical respiratory rates within the first preset time period before the current moment, and the heart rate at the current moment, multiple first historical heart rates within the first preset time period before the current moment from the vital signs database, and determine the heart rate variability corresponding to the current moment and the change in breathing depth corresponding to the current moment according to the respiratory rate at the current moment, multiple first historical respiratory rates, the heart rate at the current moment, and multiple first historical heart rates; determine the vital signs evaluation score based on the vital signs evaluation score formula according to the respiratory rate at the current moment, the heart rate at the current moment, the heart rate variability corresponding to the current moment, and the change in breathing depth corresponding to the current moment; determine the vital signs evaluation result according to the vital signs evaluation score and the preset evaluation threshold.

[0037] Furthermore, the pre-stage circuit module includes a pre-stage amplifier circuit; the pre-stage amplifier circuit includes:

[0038] A first capacitor C1, one end of the first capacitor C1 is connected to the negative polarity input terminal, and the other end is connected to the first resistor R1; the other end of the first resistor R1 is respectively connected to one end of the third capacitor C3, one end of the third resistor R3, and the negative input terminal of the first operational amplifier OP1; a second capacitor C2, one end of the second capacitor C2 is connected to the positive polarity input terminal, and the other end is connected to the second resistor R2; the other end of the second resistor R2 is respectively connected to one end of the fourth capacitor C4, one end of the fourth resistor R4, and the positive input terminal of the first operational amplifier OP1; the other ends of the fourth capacitor C4 and the fourth resistor R4 are both connected to the reference voltage terminal; the reference voltage terminal is also respectively connected to one end of the fourth capacitor C4, one end of the fourth resistor R4, and the positive input terminal of the first operational amplifier OP1; The first operational amplifier OP1 is connected to one end of the fifth resistor R5 and one end of the sixth resistor R6; the output end of the first operational amplifier OP1 is respectively connected to the other end of the third capacitor C3, the other end of the third resistor R3, one end of the fifth capacitor C5, and the negative polarity output end; the other end of the fifth resistor R5 is respectively connected to one end of the seventh resistor R7, one end of the sixth capacitor C6, and the negative input end of the second operational amplifier OP2; the other end of the sixth resistor R6 is respectively connected to the other end of the fifth capacitor C5 and the positive input end of the second operational amplifier OP2; the output end of the second operational amplifier OP2 is respectively connected to the other end of the seventh resistor R7, the other end of the sixth capacitor C6, and the positive polarity output end.

[0039] Furthermore, the first adaptive filtering module and the second adaptive filtering module both include an adaptive filtering circuit; the adaptive filtering circuit includes:

[0040] An eighth resistor R8, one end of the eighth resistor R8 is connected to the intermediate frequency signal input end, and the other end is connected to one end of the ninth resistor R9, one end of the seventh capacitor C7, and one input end of the transconductance operational amplifier OTA; the other ends of the ninth resistor R9 and the seventh capacitor C7 are both grounded; the positive power supply end of the transconductance operational amplifier OTA is respectively connected to the positive working power supply, the collector of the first NPN transistor Q1, and the collector of the second NPN transistor Q2, and the negative power supply end of the transconductance operational amplifier OTA is connected to the negative working power supply; the output end of the transconductance operational amplifier OTA is respectively connected to one end of the tenth resistor R10, one end of the eighth capacitor C8, and the base of the first NPN transistor Q1; the first NPN transistor Q The emitter of the first transistor Q1 is connected to the base of the second NPN transistor Q2, the other end of the eighth capacitor C8 is grounded, the other end of the tenth resistor R10 is respectively connected to one end of the ninth capacitor C9 and the control voltage input end, and the other end of the ninth capacitor C9 is grounded; the emitter of the second NPN transistor Q2 is respectively connected to the intermediate frequency signal output end, one end of the tenth capacitor C10, one end of the eleventh resistor R11, and one end of the twelfth resistor R12; the other end of the tenth capacitor C10 is grounded, and the other end of the eleventh resistor R11 is connected to the negative working power supply; the other end of the twelfth resistor R12 is respectively connected to the bias current input end of the transconductance operational amplifier OTA and one end of the thirteenth resistor R13, and the other end of the thirteenth resistor R13 is grounded.

[0041] In a third aspect, an embodiment of the present application provides a device comprising: a processor; a memory for storing processor-executable instructions; and a method for implementing the first aspect or any possible implementation of the first aspect when the processor executes the executable instructions.

[0042] In a fourth aspect, an embodiment of the present application provides a non-volatile computer-readable storage medium, which includes a device for storing a computer program or instruction, and when the computer program or instruction is executed, the method of the first aspect or any possible implementation method of the first aspect is implemented.

[0043] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0044] In an embodiment of the present application, a first signal and a second signal are obtained by processing an echo signal from a target area, and then respiratory filtering and heartbeat filtering are performed respectively to obtain a third signal and a fourth signal. A respiratory rate and a heartbeat rate are determined based on the third signal and the fourth signal, and the signals are stored in a vital sign database. A first filter parameter for respiratory filtering and a second filter parameter for heartbeat filtering are updated based on the respiratory rate and the heartbeat rate, thereby resolving the problem in the prior art that filtering cannot keep up with frequency changes of vital sign signals in real time, resulting in inaccurate vital sign data. This improves the accuracy of subsequently obtained respiratory rate and heartbeat rates. The heart rate variability corresponding to the current moment and the change in respiratory depth corresponding to the current moment are then determined based on the current respiratory rate and heartbeat rate, as well as multiple first historical respiratory rates and multiple first historical heartbeat rates before the current moment. A vital sign evaluation score is determined based on the current respiratory rate, the current heartbeat rate, the heart rate variability corresponding to the current moment, and the change in respiratory depth corresponding to the current moment, based on a vital sign evaluation scoring formula. The vital sign evaluation result is accurately determined based on the vital sign evaluation score and a preset evaluation threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 A flow chart of a method for evaluating vital signs based on data analysis provided in an embodiment of the present application;

[0047] Figure 2A schematic diagram of the composition of a vital sign evaluation system based on data analysis provided in an embodiment of the present application;

[0048] Figure 3 A circuit diagram of a pre-amplifier circuit provided in an embodiment of the present application;

[0049] Figure 4 A circuit diagram of an adaptive filtering circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] The following description of some of the technologies involved in the embodiments of this application is provided to facilitate understanding and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for the sake of clarity and conciseness, some descriptions of well-known functions and structures are omitted from the following description.

[0052] Contactless collection of vital sign data (such as respiratory rate and heart rate) involves processing the echo signals reflected from the human body. Because the frequency range of vital sign signals is relatively narrow, filtering is required in noisy environments. Once acquired, the vital sign data needs to be analyzed and processed to produce a vital sign evaluation result.

[0053] However, the existing filtering processing cannot follow the frequency changes of vital sign signals in real time, resulting in inaccurate vital sign data, which leads to poor accuracy of vital sign evaluation results and little reference value of the evaluation results.

[0054] For bandpass filters, the frequency of vital sign signals may drift due to individual differences or changes in physiological state (such as exercise and mood swings). Fixed bandpass filters cannot keep up with frequency changes of vital sign signals in real time, which may cause critical signals to be attenuated or even lost.

[0055] For a notch filter, if the frequency of the vital sign signal is close to the notch frequency, there is a risk of losing the vital sign signal.

[0056] Designs using Kalman filters require a preset motion model. However, vital sign signals are complex and variable. Errors in the preset motion model can lead to estimation bias, reducing the accuracy of the extracted vital sign data. Furthermore, the Kalman filter's computational complexity can reduce real-time performance in multi-target monitoring scenarios.

[0057] Against this background technology, the present disclosure provides a vital sign evaluation method based on data analysis, which can solve the problem in the existing technology that the filtering processing cannot follow the frequency changes of the vital sign signal in real time, resulting in inaccurate vital sign data, and improve the accuracy of the vital sign evaluation results.

[0058] The data analysis-based vital sign assessment method provided in the embodiments of the present disclosure may be executed by a computer or server, or other electronic devices with data processing capabilities; alternatively, the method may be executed by a processor (e.g., a central processing unit (CPU)) in the aforementioned electronic devices; alternatively, the method may be executed by an application (APP) installed in the aforementioned electronic devices that can implement the functions of the method; alternatively, the method may be executed by a functional module or unit in the aforementioned electronic devices that implements the functions of the method. The method execution entity is not limited herein.

[0059] The following is an exemplary description of the vital sign evaluation method based on data analysis with reference to the accompanying drawings.

[0060] Figure 1 : is a flow chart of a method for evaluating vital signs based on data analysis provided in an embodiment of the present application. Figure 1 This is only an execution order shown in the embodiment of the present application, and does not represent the only execution order of the vital signs evaluation method based on data analysis. Figure 1 The steps shown can be performed in parallel or in reverse. Figure 1 As shown, the method may include:

[0061] S101: Acquire echo signals from a target area, perform frequency mixing on the echo signals, and obtain two intermediate frequency signals.

[0062] The target area is the area where the human body is located, and the echo signal is the reflection signal of the radar signal transmitted to the target area.

[0063] For example, a radar sensor may transmit a millimeter wave signal to a target area and receive an echo signal of the millimeter wave signal in the target area.

[0064] For example, the radar sensor can be configured with an update frequency of 16 Hz to 20 Hz to meet the requirements of vital sign detection.

[0065] For example, after the echo signal is acquired, the echo signal may be mixed with a local oscillator signal to obtain two orthogonal intermediate frequency signals.

[0066] S102 : Perform intermediate frequency amplification processing on the two intermediate frequency signals to obtain a first signal and a second signal.

[0067] For example, a high-input-impedance, low-noise operational amplifier may be used to construct a voltage follower to achieve impedance decoupling and shift the two intermediate-frequency signals into a processable range by applying a bias voltage.

[0068] S103 : Perform respiratory filtering processing and heartbeat filtering processing on the first signal and the second signal, respectively, to obtain a third signal and a fourth signal.

[0069] The first filter parameter of the respiratory filtering process is different from the second filter parameter of the heartbeat filtering process. Both the first filter parameter and the second filter parameter include corresponding filter control voltage and filter bandwidth.

[0070] Exemplarily, the first signal and the second signal can be filtered separately by two band-pass filters, and different filter parameters (i.e., first filtering parameters or second filtering parameters) can be set for the two band-pass filters according to the filtering requirements (i.e., whether to perform respiratory filtering or heartbeat filtering); the filtering parameters can also include the center frequency.

[0071] It can be understood that the third signal obtained by performing the breathing filtering process corresponds to the breathing of the human body, and the fourth signal obtained by performing the heartbeat filtering process corresponds to the heartbeat of the human body.

[0072] S104 , determining the respiratory rate and the heart rate according to the third signal and the fourth signal respectively, and storing them in a vital sign database.

[0073] It can be understood that after obtaining the third signal and the fourth signal, since the third signal and the fourth signal are intermediate frequency signals, the third signal and the fourth signal can be demodulated and baseband processed (analog-to-digital conversion and orthogonal demodulation of the intermediate frequency signal, etc.).

[0074] Exemplarily, the third signal and the fourth signal may be processed according to a vital sign data extraction algorithm to obtain a respiratory rate and a heart rate, respectively.

[0075] For example, the vital sign data extraction algorithm may include an empirical mode decomposition (EMD) algorithm, a variational mode decomposition (VMD) algorithm, a wavelet transform algorithm, etc., without limitation thereto.

[0076] For example, the vital signs database can be deployed locally or in the cloud, and the obtained respiratory rate and heart rate are matched with the detected person, and are encrypted using the AES-256 (Advanced Encryption Standard-256bit) encryption algorithm before being recorded and stored.

[0077] In some embodiments, determining the respiratory rate and the heart rate based on the third signal and the fourth signal, respectively, includes:

[0078] The frequency determination step is performed on the third signal and the fourth signal respectively to obtain the respiratory frequency and the heart rate.

[0079] The frequency determination step includes:

[0080] Determine multiple observation samples based on the third signal or the fourth signal; determine an autocorrelation matrix based on the multiple observation samples; perform eigenvalue decomposition on the autocorrelation matrix to obtain multiple noise subspace basis vectors; construct a target spectrum based on the multiple noise subspace basis vectors; perform peak search on the target spectrum, and determine the frequency corresponding to the peak as the respiratory rate or the heart rate.

[0081] Exemplarily, one-dimensional fast Fourier transform processing may be performed on the third signal or the fourth signal to obtain a plurality of observation samples.

[0082] For example, assume that the order of the autocorrelation matrix is , the number of observation samples is , then The observation samples can be expressed as .

[0083] Autocorrelation matrix It can be expressed as:

[0084]

[0085] in, express The conjugate transpose of express The conjugation of .

[0086] Autocorrelation matrix Perform eigenvalue decomposition to obtain the noise subspace basis vectors. The normalized eigenvector corresponding to the minimum eigenvalue is a set of noise subspace basis vectors. Indicates the number of radar targets.

[0087] Furthermore, the target spectrum is a MUSIC spectrum, and the target spectrum is constructed according to multiple noise subspace basis vectors, including:

[0088] According to multiple noise subspace basis vectors, the MUSIC spectrum is constructed based on the target spectrum determination formula; the target spectrum determination formula is shown in formula (5):

[0089] (5)

[0090] In formula (5), Indicates frequency The signal strength at represents the order of the autocorrelation matrix, represents the number of observation samples, Indicates frequency The corresponding direction vector, Represents the noise subspace matrix corresponding to multiple noise subspace basis vectors, express The index number of the column vector in .

[0091] In this way, the respiratory rate and heart rate can be obtained quickly and accurately.

[0092] S105 . Update the first filter parameter and the second filter parameter according to the respiratory frequency and the heart rate respectively.

[0093] For example, the obtained respiratory rate and heart rate can be used to update parameters such as filter control voltage and filter bandwidth to reduce the offset between the filter parameters and vital signs data and avoid signal loss, thereby improving the accuracy of the subsequently obtained respiratory rate and heart rate.

[0094] Specifically, S105 may include S201 and S202.

[0095] S201 , updating a filter control voltage corresponding to a first filter parameter and a filter control voltage corresponding to a second filter parameter according to a respiratory frequency and a heart rate based on a control voltage adjustment formula.

[0096] The control voltage adjustment formula is shown in formula (1):

[0097] (1)

[0098] In formula (1), represents the filter control voltage, represents the proportional gain coefficient, Indicates respiratory rate or heart rate, represents the filter center frequency corresponding to the respiratory rate or heart rate, represents the integral gain coefficient, Indicates the length of the integration time window, represents the integration variable.

[0099] For example, considering adjusting the speed while avoiding oscillation, the proportional gain coefficient can be set to 0.8 , the integral gain coefficient can be set to 0.05 ; To avoid errors caused by infinite accumulation of integral terms, the duration of the integral time window is set to 5 seconds.

[0100] Illustratively, after obtaining the filter control voltage corresponding to the respiratory frequency, the filter control voltage for respiratory filtering processing may be adjusted; after obtaining the filter control voltage corresponding to the heartbeat frequency, the filter control voltage for heartbeat filtering processing may be adjusted.

[0101] S202 : updating the filter bandwidth corresponding to the first filter parameter and the filter bandwidth corresponding to the second filter parameter based on a bandwidth adjustment formula according to the power of the third signal corresponding to the respiratory frequency and the power of the fourth signal corresponding to the heart rate.

[0102] The bandwidth adjustment formula is shown in formula (2):

[0103] (2)

[0104] In formula (3), represents the filter bandwidth, represents the minimum bandwidth of the filter, represents the instantaneous adjustment coefficient, Indicates taking the maximum value, represents the power of the third signal corresponding to the respiratory frequency or the power of the fourth signal corresponding to the heart rate, Indicates the preset power threshold, Indicates the preset dead zone width.

[0105] For example, the minimum bandwidth of the filter can be 3 ; Considering the control response speed, the instantaneous adjustment coefficient can be set to 0.15 ; The preset power threshold can be -40 ; To avoid unnecessary frequent adjustments, the preset dead zone width can be set to 0.15 , that is, only when The filter bandwidth is adjusted accordingly.

[0106] For example, the power of the third signal or the fourth signal may be determined by spectrum analyzer measurement, fast Fourier transform, or the like, without limitation thereto.

[0107] S106. Obtain the respiratory rate at the current moment, multiple first historical respiratory rates within a first preset time period before the current moment, and the heart rate at the current moment, multiple first historical heart rates within a first preset time period before the current moment from the vital signs database; determine the heart rate variability corresponding to the current moment and the change in breathing depth corresponding to the current moment based on the respiratory rate at the current moment, the multiple first historical respiratory rates, the heart rate at the current moment, and the multiple first historical heart rates.

[0108] For example, the first preset duration may be 5 minutes or 10 minutes, and there is no limitation thereto.

[0109] For example, the heart rate variability corresponding to the current moment can be determined based on the heart rate frequency at the current moment and multiple first historical heart rates, based on the heart rate variability calculation formula. The heart rate variability calculation formula is shown in formula (7):

[0110] (7)

[0111] In formula (7), Indicates the heart rate variability corresponding to the current moment, Represents the sum of the number of first historical heartbeat frequencies and the current heartbeat frequency (for example, if the number of first historical heartbeat frequencies is 9, then ), express The first of the heart rate Heart rate, express The average heart rate.

[0112] For example, the breathing depth change corresponding to the current moment can be determined based on the breathing frequency at the current moment and the multiple first historical breathing frequencies and the breathing depth change calculation formula. The breathing depth change calculation formula is shown in formula (8):

[0113] (8)

[0114] In formula (8), Indicates the change in breathing depth corresponding to the current moment. represents the sum of the number of first historical respiratory frequencies and the current respiratory frequency (for example, if the number of first historical respiratory frequencies is 9, then ), express The respiratory rate of respiratory rate, express The average respiratory rate.

[0115] S107. Determine a vital sign evaluation score based on the vital sign evaluation score formula according to the current respiratory rate, the current heart rate, the heart rate variability corresponding to the current moment, and the change in breathing depth corresponding to the current moment.

[0116] Specifically, S107 may include S301 to S305.

[0117] S301 : Determine a respiratory evaluation score according to the current respiratory frequency and a respiratory evaluation score formula.

[0118] The breathing evaluation score formula is shown in formula (3):

[0119] (3)

[0120] In formula (3), represents the respiratory evaluation score, Represents the respiratory rate, represents the optimal respiratory rate, Indicates taking the maximum value, Indicates tachypnea rate, Indicates bradypnea rate.

[0121] For example, the optimal breathing rate may be determined based on the age of the detected person.

[0122] S302: Determine a heartbeat evaluation score according to the current heartbeat frequency and a heartbeat evaluation score formula.

[0123] The heartbeat evaluation score formula is shown in formula (4):

[0124] (4)

[0125] In formula (4), Indicates the heartbeat evaluation score, Indicates the heart rate, Indicates the optimal heart rate, Indicates taking the maximum value, Indicates the heart rate. Indicates a slow heartbeat rate.

[0126] For example, the optimal heart rate can be determined based on the age of the person being detected.

[0127] S303: Determine a heart rate variability evaluation score based on the heart rate variability corresponding to the current moment.

[0128] For example, the heart rate variability corresponding to the current moment may be determined as the heart rate variability evaluation score.

[0129] S304: Determine a breathing depth change evaluation score based on the breathing depth change corresponding to the current moment.

[0130] For example, the breathing depth change corresponding to the current moment may be determined as the breathing depth change evaluation score.

[0131] S305 : Determine a vital sign evaluation score based on the vital sign evaluation score formula according to the respiration evaluation score, the heartbeat evaluation score, the heart rate variability evaluation score, and the respiratory depth change evaluation score.

[0132] For example, the vital sign evaluation score formula may be a model for calculating the sum of a respiration evaluation score, a heartbeat evaluation score, a heart rate variability evaluation score, and a respiration depth change evaluation score, and this is not limited thereto.

[0133] In some embodiments, the vital sign evaluation score formula may be as shown in formula (6):

[0134] (6)

[0135] In formula (6), represents the vital signs assessment score, represents the respiratory evaluation score, Indicates the heartbeat evaluation score, represents the heart rate variability evaluation score, Indicates the breathing depth change evaluation score, 、 、 、 They represent the weight of the respiration evaluation score, the weight of the heartbeat evaluation score, the weight of the heart rate variability evaluation score, and the weight of the breathing depth change evaluation score respectively.

[0136] For example, the weights of the respiration evaluation score, the heartbeat evaluation score, the heart rate variability evaluation score, and the respiration depth change evaluation score can be preset according to the age, illness status, etc. of the person being tested, and there is no restriction on this.

[0137] It can be understood that the vital sign evaluation score is between 0 and 1, and a larger vital sign evaluation score indicates a better health status.

[0138] Furthermore, the weight of the breathing evaluation score, the weight of the heartbeat evaluation score, the weight of the heart rate variability evaluation score, and the weight of the breathing depth change evaluation score can be updated respectively based on multiple historical breathing evaluation scores, multiple historical heartbeat evaluation scores, multiple historical heart rate variability evaluation scores, and multiple historical breathing depth change evaluation scores within a second preset time period before the current moment.

[0139] For example, the means and standard deviations of multiple historical breathing evaluation scores, multiple historical heartbeat evaluation scores, multiple historical heart rate variability evaluation scores, and multiple historical breathing depth change evaluation scores can be calculated respectively. When the fluctuation of a certain evaluation score is large, its corresponding weight can be increased to increase its influence on the vital signs evaluation results. Otherwise, the weight can be reduced, so that the vital signs evaluation results can better reflect the situation of unstable factors and improve the accuracy of the vital signs evaluation results.

[0140] In some possible embodiments, the weight of the respiration evaluation score, the weight of the heartbeat evaluation score, the weight of the heart rate variability evaluation score, and the weight of the respiration depth change evaluation score can also be updated separately according to the age, illness status, or exercise status of the person being tested.

[0141] S108. Determine the vital sign evaluation result according to the vital sign evaluation score and the preset evaluation threshold.

[0142] Continuing with the above example, the preset evaluation thresholds may include (0, 0.5), [0.5, 0.65) poor, [0.65, 0.75) fair, and [0.75, 1) good, and the corresponding vital sign evaluation results are critical, poor, fair, and good, respectively.

[0143] In an embodiment of the present application, a first signal and a second signal are obtained by processing an echo signal from a target area, and then respiratory filtering and heartbeat filtering are performed respectively to obtain a third signal and a fourth signal. A respiratory rate and a heartbeat rate are determined based on the third signal and the fourth signal, and the signals are stored in a vital sign database. A first filter parameter for respiratory filtering and a second filter parameter for heartbeat filtering are updated based on the respiratory rate and the heartbeat rate, thereby resolving the problem in the prior art that filtering cannot keep up with frequency changes of vital sign signals in real time, resulting in inaccurate vital sign data. This improves the accuracy of subsequently obtained respiratory rate and heartbeat rates. The heart rate variability corresponding to the current moment and the change in respiratory depth corresponding to the current moment are then determined based on the current respiratory rate and heartbeat rate, as well as multiple first historical respiratory rates and multiple first historical heartbeat rates before the current moment. A vital sign evaluation score is determined based on the current respiratory rate, the current heartbeat rate, the heart rate variability corresponding to the current moment, and the change in respiratory depth corresponding to the current moment, based on a vital sign evaluation scoring formula. The vital sign evaluation result is accurately determined based on the vital sign evaluation score and a preset evaluation threshold.

[0144] Although this application provides method operation steps such as embodiments or flowcharts, more or fewer operation steps may be included based on routine or non-creative work. The order of steps listed in this embodiment is only one way of executing the steps among many, and does not represent the only execution order. When an actual device or client product executes, the method can be executed sequentially according to the embodiment or the accompanying drawings, or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0145] like Figure 2 As shown, the embodiment of the present application also provides a vital sign evaluation system based on data analysis. The system includes:

[0146] Front-end radar module 410, intermediate frequency processing module 420, control processing module 430, vital sign evaluation module 440, intermediate frequency processing module 420 includes front-stage circuit module 421, first adaptive filtering module 422, second adaptive filtering module 423;

[0147] The front-end radar module 410 is used to transmit radar signals to a target area, receive echo signals from the target area, perform frequency mixing on the echo signals, obtain two intermediate frequency signals, and send them to the front-end circuit module. The target area is the area where the human body is located, and the echo signals are reflections of the radar signals transmitted to the target area.

[0148] The front-stage circuit module 421 is used to perform intermediate frequency amplification processing on the two intermediate frequency signals to obtain a first signal and a second signal;

[0149] a first adaptive filtering module 422 configured to perform respiratory filtering processing on the first signal and the second signal to obtain a third signal; and a second adaptive filtering module 423 configured to perform heartbeat filtering processing on the first signal and the second signal to obtain a fourth signal; wherein the first filtering parameter of the respiratory filtering processing is different from the second filtering parameter of the heartbeat filtering processing, and both the first filtering parameter and the second filtering parameter include a corresponding filter control voltage and a filter bandwidth;

[0150] The control processing module 430 is used to determine the respiratory rate and the heart rate according to the third signal and the fourth signal, respectively, and store them in the vital signs database; and is also used to update the first filter parameter and the second filter parameter according to the respiratory rate and the heart rate, respectively;

[0151] The vital signs evaluation module 440 is used to obtain the respiratory frequency at the current moment, multiple first historical respiratory frequencies within a first preset time period before the current moment, and the heart rate at the current moment, multiple first historical heart rates within a first preset time period before the current moment from the vital signs database; determine the heart rate variability corresponding to the current moment and the change in breathing depth corresponding to the current moment based on the respiratory frequency at the current moment, multiple first historical respiratory frequencies, the heart rate at the current moment, and multiple first historical heart rates; determine the vital signs evaluation score based on the vital signs evaluation score formula based on the respiratory frequency at the current moment, the heart rate variability corresponding to the current moment, and the change in breathing depth corresponding to the current moment; and determine the vital signs evaluation result based on the vital signs evaluation score and the preset evaluation threshold.

[0152] Further, Figure 3 The circuit diagram of the pre-amplifier circuit provided in the embodiment of the present application is shown in FIG. Figure 3 The pre-stage circuit module 421 includes a pre-stage amplifier circuit; the pre-stage amplifier circuit includes:

[0153] The first capacitor C1, one end of the first capacitor C1 is connected to the negative polarity input end (ie Figure 3 The other end of the first resistor R1 is connected to one end of the third capacitor C3, one end of the third resistor R3, and the negative input terminal of the first operational amplifier OP1.

[0154] The second capacitor C2, one end of the second capacitor C2 is connected to the positive polarity input terminal (ie Figure 3 IF_P in the figure), and the other end is connected to the second resistor R2; the other end of the second resistor R2 is respectively connected to one end of the fourth capacitor C4, one end of the fourth resistor R4, and the positive input terminal of the first operational amplifier OP1; the other ends of the fourth capacitor C4 and the fourth resistor R4 are both connected to the reference voltage terminal (i.e. Figure 3The reference voltage terminal is also connected to one end of the fifth resistor R5 and one end of the sixth resistor R6 respectively.

[0155] The output terminal of the first operational amplifier OP1 is connected to the other end of the third capacitor C3, the other end of the third resistor R3, one end of the fifth capacitor C5, the negative polarity output terminal (i.e. Figure 3 IF_L) connection in.

[0156] The other end of the fifth resistor R5 is respectively connected to one end of the seventh resistor R7, one end of the sixth capacitor C6, and the negative input end of the second operational amplifier OP2; the other end of the sixth resistor R6 is respectively connected to the other end of the fifth capacitor C5 and the positive input end of the second operational amplifier OP2.

[0157] The output terminal of the second operational amplifier OP2 is connected to the other end of the seventh resistor R7, the other end of the sixth capacitor C6, the positive polarity output terminal (ie Figure 3 IF_H) connection in.

[0158] Exemplarily, a dual-channel operational amplifier may be used to implement the first operational amplifier OP1 and the second operational amplifier OP2 .

[0159] The preamplifier circuit is used for impedance matching, signal isolation, and amplitude conditioning. The present invention uses a high-input-impedance, low-noise operational amplifier to construct a voltage follower, achieving impedance decoupling and shifting the bipolar signal to a range that can be processed by the analog-to-digital converter by applying a bias voltage.

[0160] Furthermore, the first adaptive filtering module and the second adaptive filtering module both include adaptive filtering circuits. Figure 4 This is a circuit diagram of an adaptive filtering circuit provided in an embodiment of the present application. Figure 4 , the adaptive filtering circuit includes:

[0161] The eighth resistor R8, one end of the eighth resistor R8 is connected to the intermediate frequency signal input end (ie Figure 4 The other end of the ninth resistor R9 and the seventh capacitor C7 are connected to one end of the ninth resistor R9, one end of the seventh capacitor C7, and an input end of the transconductance operational amplifier OTA; the other ends of the ninth resistor R9 and the seventh capacitor C7 are grounded.

[0162] The positive power supply terminal of the transconductance operational amplifier OTA is connected to the positive working power supply (i.e. Figure 4 The collector of the first NPN transistor Q1 and the collector of the second NPN transistor Q2 are connected, and the negative power supply terminal of the transconductance operational amplifier OTA is connected to the negative working power supply (i.e. Figure 4 -VCC) connection in the .

[0163] The output end of the transconductance operational amplifier OTA is respectively connected to one end of the tenth resistor R10, one end of the eighth capacitor C8, and the base of the first NPN transistor Q1; the emitter of the first NPN transistor Q1 is connected to the base of the second NPN transistor Q2, the other end of the eighth capacitor C8 is grounded, and the other end of the tenth resistor R10 is respectively connected to one end of the ninth capacitor C9 and the control voltage input end (i.e. Figure 4 The other end of the ninth capacitor C9 is grounded.

[0164] The emitter of the second NPN transistor Q2 is connected to the intermediate frequency signal output terminal (i.e. Figure 4 IF_OUT in), one end of the tenth capacitor C10, one end of the eleventh resistor R11, and one end of the twelfth resistor R12 are connected; the other end of the tenth capacitor C10 is grounded, and the other end of the eleventh resistor R11 is connected to the negative working power supply (i.e. Figure 4 -VCC) connection in the .

[0165] The other end of the twelfth resistor R12 is connected to the bias current input end of the transconductance operational amplifier OTA and one end of the thirteenth resistor R13 respectively, and the other end of the thirteenth resistor R13 is grounded.

[0166] It can be understood that the other input terminal of the transconductance operational amplifier OTA is not connected to other components or ports.

[0167] The beneficial effects and specific implementation methods of this system embodiment can be referred to the aforementioned method embodiment, and will not be repeated here.

[0168] Some modules in the system described herein can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media, including storage devices.

[0169] The devices or modules described in the above application embodiments can be implemented by computer chips or physical devices, or by products with certain functions. For ease of description, the above devices are described separately by function in various modules. When implementing the embodiments of this application, the functions of each module can be implemented in the same or multiple software and / or hardware. Of course, a module that implements a certain function can also be implemented by combining multiple sub-modules or sub-units.

[0170] The methods, devices, or modules described herein can be implemented in the form of computer-readable program code. The controller can be implemented in any suitable manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller can also be implemented as part of the memory control logic. Those skilled in the art will also appreciate that, in addition to implementing the controller in pure computer-readable program code, the controller can also be implemented in the form of logic gates, switches, an application-specific integrated circuit, a programmable logic controller, an embedded microcontroller, etc. by logically programming the method steps. Therefore, such a controller can be considered a hardware component, and the devices included therein for implementing various functions can also be considered as structures within the hardware component. Or even, the means for implementing various functions may be considered to be both a software module for implementing the method and a structure within a hardware component.

[0171] An embodiment of the present application further provides a device comprising: a processor; a memory for storing processor-executable instructions; and when the processor executes the executable instructions, the method described in the embodiment of the present application is implemented.

[0172] The embodiments of the present application also provide a non-volatile computer-readable storage medium having a computer program or instruction stored thereon. When the computer program or instruction is executed, the method described in the embodiments of the present application is implemented.

[0173] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist independently, or two or more modules may be integrated into one module.

[0174] The above-mentioned storage media include, but are not limited to, random access memory (RAM), read-only memory (ROM), cache, hard disk drive (HDD), or memory card. Such memory can be used to store computer program instructions.

[0175] Through the description of the above implementation methods, it can be seen that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, or can be embodied through the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a mobile terminal, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application or certain parts of the embodiments.

[0176] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments. All or part of this application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, mobile communication terminals, multi-processor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc.

[0177] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A vital sign evaluation system based on data analysis, characterized in that: include: Front-end radar module, intermediate frequency processing module, control processing module, vital sign evaluation module, the intermediate frequency processing module includes a front-stage circuit module, a first adaptive filtering module, and a second adaptive filtering module; The front-end radar module is configured to transmit a radar signal to a target area, receive an echo signal from the target area, perform frequency mixing on the echo signal to obtain two intermediate frequency signals, and transmit the two intermediate frequency signals to the front-end circuit module; wherein the target area is an area where a human body is located, and the echo signal is a reflection signal of the radar signal transmitted to the target area; The front-stage circuit module is used to perform intermediate frequency amplification processing on the two intermediate frequency signals to obtain a first signal and a second signal; The first adaptive filtering module is configured to perform respiratory filtering processing on the first signal and the second signal to obtain a third signal; the second adaptive filtering module is configured to perform heartbeat filtering processing on the first signal and the second signal to obtain a fourth signal; wherein a first filtering parameter of the respiratory filtering processing is different from a second filtering parameter of the heartbeat filtering processing, and both the first filtering parameter and the second filtering parameter include a corresponding filter control voltage and a filter bandwidth; The control processing module is used to determine the respiratory rate and the heart rate according to the third signal and the fourth signal, and store them in the vital signs database; and is also used to update the first filtering parameter and the second filtering parameter according to the respiratory rate and the heart rate, respectively; The vital signs evaluation module is configured to obtain, from a vital signs database, the respiratory rate at a current moment, a plurality of first historical respiratory rates within a first preset time period before the current moment, and the heart rate at a current moment, a plurality of first historical heart rates within a first preset time period before the current moment; determine, based on the respiratory rate at the current moment, the plurality of first historical respiratory rates, the heart rate at the current moment, and the plurality of first historical heart rates, the heart rate variability corresponding to the current moment and the change in breathing depth corresponding to the current moment; determine, based on the vital signs evaluation score formula, a vital signs evaluation score based on the respiratory rate at the current moment, the heart rate at the current moment, the heart rate variability corresponding to the current moment, and the change in breathing depth corresponding to the current moment; and determine a vital signs evaluation result based on the vital signs evaluation score and a preset evaluation threshold; The method of determining the vital sign evaluation score based on the current respiratory rate, the current heart rate, the heart rate variability corresponding to the current moment, and the change in breathing depth corresponding to the current moment, based on the vital sign evaluation score formula, includes: Determine a respiratory evaluation score based on the respiratory rate at the current moment and the respiratory evaluation score formula; determine a heartbeat evaluation score based on the heartbeat evaluation score formula according to the heart rate at the current moment; determine a heart rate variability evaluation score based on the heart rate variability corresponding to the current moment; determine a respiratory depth change evaluation score based on the respiratory evaluation score, the heartbeat evaluation score, the heart rate variability evaluation score, and the respiratory depth change evaluation score, and determine a vital sign evaluation score based on the vital sign evaluation score formula; The respiratory evaluation score formula is shown in formula (3): （3） In formula (3), represents the respiratory evaluation score, Represents the respiratory rate, represents the optimal respiratory rate, Indicates taking the maximum value, Indicates tachypnea rate, Indicates bradypnea rate; The heartbeat evaluation score formula is shown in formula (4): （4） In formula (4), Indicates the heartbeat evaluation score, Indicates the heart rate, Indicates the optimal heart rate, Indicates taking the maximum value, Indicates the heart rate. Indicates a slow heartbeat rate.

2. The system according to claim 1, wherein: The front-stage circuit module includes a front-stage amplifier circuit; the front-stage amplifier circuit includes: A first capacitor C1, one end of the first capacitor C1 is connected to the negative input terminal, and the other end is connected to the first resistor R1; the other end of the first resistor R1 is respectively connected to one end of the third capacitor C3, one end of the third resistor R3, and the negative input terminal of the first operational amplifier OP1; A second capacitor C2, one end of the second capacitor C2 is connected to the positive polarity input terminal, and the other end is connected to the second resistor R2; the other end of the second resistor R2 is respectively connected to one end of a fourth capacitor C4, one end of a fourth resistor R4, and the positive input terminal of the first operational amplifier OP1; the other ends of the fourth capacitor C4 and the fourth resistor R4 are both connected to the reference voltage terminal; the reference voltage terminal is also respectively connected to one end of a fifth resistor R5 and one end of a sixth resistor R6; The output end of the first operational amplifier OP1 is respectively connected to the other end of the third capacitor C3, the other end of the third resistor R3, one end of the fifth capacitor C5, and the negative polarity output end; The other end of the fifth resistor R5 is respectively connected to one end of the seventh resistor R7, one end of the sixth capacitor C6, and the negative input terminal of the second operational amplifier OP2; the other end of the sixth resistor R6 is respectively connected to the other end of the fifth capacitor C5 and the positive input terminal of the second operational amplifier OP2; The output end of the second operational amplifier OP2 is connected to the other end of the seventh resistor R7, the other end of the sixth capacitor C6, and the positive output end respectively.

3. The system according to claim 1, wherein: The first adaptive filtering module and the second adaptive filtering module both include an adaptive filtering circuit; the adaptive filtering circuit includes: an eighth resistor R8, one end of the eighth resistor R8 being connected to the intermediate frequency signal input terminal, and the other end being connected to one end of a ninth resistor R9, one end of a seventh capacitor C7, and one input terminal of a transconductance operational amplifier OTA; the other ends of the ninth resistor R9 and the seventh capacitor C7 being grounded; The positive power supply terminal of the transconductance operational amplifier OTA is connected to the positive working power supply, the collector of the first NPN transistor Q1, and the collector of the second NPN transistor Q2 respectively, and the negative power supply terminal of the transconductance operational amplifier OTA is connected to the negative working power supply; An output end of the transconductance operational amplifier OTA is respectively connected to one end of a tenth resistor R10, one end of an eighth capacitor C8, and the base of a first NPN transistor Q1; an emitter of the first NPN transistor Q1 is connected to the base of a second NPN transistor Q2, and the other end of the eighth capacitor C8 is grounded. The other end of the tenth resistor R10 is respectively connected to one end of a ninth capacitor C9 and the control voltage input end, and the other end of the ninth capacitor C9 is grounded. The emitter of the second NPN transistor Q2 is connected to the intermediate frequency signal output terminal, one end of the tenth capacitor C10, one end of the eleventh resistor R11, and one end of the twelfth resistor R12 respectively; the other end of the tenth capacitor C10 is grounded, and the other end of the eleventh resistor R11 is connected to the negative working power supply; The other end of the twelfth resistor R12 is connected to the bias current input end of the transconductance operational amplifier OTA and one end of the thirteenth resistor R13 respectively, and the other end of the thirteenth resistor R13 is grounded.

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