Wrist blood vessel hardness detector

Abstract

The invention discloses a wrist type blood vessel hardness detector, and relates to the technical field of medical instruments. The wrist type blood vessel hardness detector comprises a wrist strap and a detection box connected with the wrist strap, an air bag is placed on the inner side of the wrist strap, the air bag wraps a vibration sensor used for obtaining blood vessel vibration signals, and a pressure sensor is arranged at the bottom of the detection box. The wrist type blood vessel hardness detector is worn on the wrist of a user, the air bag is controlled to be inflated and deflated according to a pressure signal detected by the pressure sensor and / or a blood vessel vibration signal detected by the vibration sensor, and a blood vessel vibration signal in a target time period starts to be collected when the air bag is deflated; and performing blood vessel hardness calculation based on the blood vessel vibration signal in the target time period. The wrist type blood vessel hardness detector can be realized only by configuring the vibration sensor and the mainboard, is convenient to operate, light and portable, and can obtain the blood vessel health condition of a user at any time in different environments.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a wrist-type vascular hardness tester. Background Art

[0002] With the increasing aging population, the morbidity and mortality of cardiovascular disease will continue to rise, increasing the demand for early screening for cardiovascular disease. Arteriosclerosis is an independent predictor of cardiovascular disease. Existing noninvasive methods for detecting vascular sclerosis are primarily based on pulse wave velocity. However, this method requires relatively large equipment and relies on hospitals and physical examination centers. The complex and specialized operation and relatively high price limit its application in at-home testing. Given the principle of pulse wave velocity in measuring vascular stiffness, this method is difficult to apply to portable devices. Summary of the Invention

[0003] The purpose of this application is to provide a wrist-type vascular hardness tester that is easy to operate, lightweight and portable, and can obtain the user's vascular health status at any time in different environments.

[0004] To achieve the above objectives, this application provides the following solutions.

[0005] In a first aspect, the present application provides a wrist-type vascular hardness tester, comprising: a wristband, an airbag, a pressure sensor, a vibration sensor, and a detection box, wherein the airbag, the vibration sensor, and the detection box are all arranged on the wristband; the pressure sensor is arranged at the bottom of the detection box;

[0006] The detection box is provided with an air pump, an air valve and a main board; the air pump is connected to the air bag through the air valve;

[0007] The vibration sensor and the pressure sensor are both connected to the main board, and the main board is also connected to the control end of the air pump and the control end of the air valve;

[0008] When in use, the wristband is wrapped around the user's wrist, the airbag and the vibration sensor are located between the wristband and the user's wrist, and the pressure sensor is located between the detection box and the user's wrist; the vibration sensor is used to collect the user's blood vessel vibration signal and send the blood vessel vibration signal to the mainboard, and the pressure sensor is used to detect the pressure signal and send the pressure signal to the mainboard;

[0009] The main board is used to control the air valve and the air pump to inflate and deflate the airbag according to the blood vessel vibration signal and / or the pressure signal, and to extract the blood vessel vibration signal of a target time period, and calculate the blood vessel hardness according to the blood vessel vibration signal of the target time period. The target time period is the deflation time period, that is, the time period between the complete collapse of the blood vessel and the complete recovery of the blood vessel.

[0010] Optionally, in terms of controlling the air valve and the air pump to inflate and deflate the airbag based on the blood vessel vibration signal, the mainboard is specifically configured to:

[0011] When receiving a blood vessel hardness detection instruction, controlling the air valve and the air pump to inflate the airbag;

[0012] During the inflation process, within a preset time period after the blood vessel vibration signal and / or the pressure signal indicate that the blood vessel has completely collapsed, controlling the air valve and the air pump to deflate the airbag;

[0013] During the deflation process, when the blood vessel vibration signal and / or the pressure signal indicates that the blood vessel has fully recovered, the air valve and the air pump are controlled to stop deflation of the airbag.

[0014] Optionally, in terms of calculating blood vessel hardness based on the blood vessel vibration signal in the target time period, the main board is specifically configured to:

[0015] Extracting target time-frequency domain features of the vascular oscillation signal in a target time period; the target time-frequency domain features are time series features that are significantly correlated with vascular hardness;

[0016] The vascular hardness is calculated using a vascular hardness calculation model according to the target time-frequency domain characteristics; the vascular hardness calculation model characterizes the relationship between the target time-frequency domain characteristics and the vascular hardness.

[0017] Optionally, extracting target time-frequency domain features of the blood vessel oscillation signal in a target time period may further include:

[0018] Detrending, denoising and smoothing are performed on the blood vessel vibration signal.

[0019] Optionally, the target time-frequency domain features include: one or more of: absolute maximum amplitude, center of mass, skewness, waveform index, center of gravity frequency, frequency corresponding to maximum power value, natural frequency and average frequency.

[0020] Optionally, the calculation formula of the centroid is:

[0021] ;

[0022] in, is the center of mass, 、 、 are the coordinates of the 1st, 2nd and nth frames of the blood vessel vibration signal in the target coordinate system, respectively. The target coordinate system is a coordinate system established according to the positions of the blood vessel vibration signals in each frame. 、 and are the maximum amplitudes of the blood vessel vibration signal in the 1st frame, the 2nd frame, and the nth frame respectively, and n is the number of frames of the blood vessel vibration signal in the target time period.

[0023] Optionally, the wrist-type vascular hardness tester further comprises: a 3D sensor for step counting;

[0024] The 3D pedometer sensor is disposed in the detection box, and the 3D pedometer sensor is connected to the mainboard. The mainboard is further configured to measure the number of steps according to the detection signal of the 3D pedometer sensor.

[0025] The main board is also used to obtain the pressure signal detected by the pressure sensor as the first wristband pressure when the blood vessel vibration signal or pressure signal indicates that the blood vessel has collapsed; and to obtain the pressure signal detected by the pressure sensor as the second wristband pressure when the blood vessel vibration signal or pressure signal indicates that the blood vessel has fully recovered.

[0026] Optionally, the wrist-type vascular hardness tester also includes: an accelerometer, which is arranged in the detection box and connected to the main board. The main board is also used to identify the user's movement state based on the acceleration signal detected by the accelerometer to ensure that the user is in a resting state during the measurement process.

[0027] Optionally, the wrist-type vascular hardness tester also includes: a motor vibrator, which is arranged in the detection box, and the control end of the motor vibrator is connected to the main board. The main board is also used to control the motor vibrator to vibrate when the vascular hardness meets the warning conditions.

[0028] Optionally, the mainboard includes: a computing module, a Bluetooth module, a power management module, a touch chip, a storage module and a display module;

[0029] The Bluetooth module, the touch chip, the storage module and the display module are all connected to the computing module;

[0030] The power management module is connected to the computing module, the Bluetooth module, the touch chip, the storage module and the display module respectively.

[0031] According to the specific embodiments provided in this application, this application has the following technical effects.

[0032] The present application provides a wrist-type vascular hardness tester, comprising a wristband and a detection box connected thereto, an airbag placed inside the wristband, the airbag enclosing a vibration sensor for obtaining a vascular vibration signal, and a pressure sensor provided at the bottom of the detection box. The wrist-type vascular hardness tester is worn on the wrist of the user, and the inflation and deflation of the airbag are controlled according to the pressure signal detected by the pressure sensor and the vascular vibration signal detected by the vibration sensor, and the vascular vibration signal of the target time period is extracted, and the vascular hardness is calculated based on the vascular vibration signal of the target time period. The wrist-type vascular hardness tester of the present application only needs to be configured with a vibration sensor and a mainboard, and is easy to operate, lightweight and portable, and can obtain the user's vascular health status at any time in different environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 This is a structural schematic diagram of a wrist-type vascular hardness tester provided in one embodiment of the present application.

[0035] Figure 2 A schematic structural diagram of a detection box provided in one embodiment of the present application.

[0036] Figure 3 A schematic diagram of the structure of a mainboard provided in one embodiment of the present application.

[0037] Figure 4 This is a structural principle diagram of a wrist-type vascular hardness tester provided in one embodiment of the present application.

[0038] Figure 5 A comparison diagram of the original blood vessel vibration signal and the pre-processed blood vessel vibration signal provided in an embodiment of the present application.

[0039] Figure 6 This is a statistical result diagram of the natural frequency of blood vessel vibration signals in the vascular sclerosis group and the control group provided in one embodiment of the present application.

[0040] Description of reference numerals:

[0041] 1. Detection box; 11. Pressure sensor; 12. 3D sensor for pedometer; 13. Mainboard; 14. Battery; 15. Air pump; 16. Air valve; 2. Wristband; 21. Airbag; 22. Vibration sensor; 131. Bluetooth module; 132. Digital signal processor; 133. Running memory; 134. Flash memory; 135. Power management module; 136. Motor vibrator; 137. Touch chip. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0043] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0044] Korotkoff sounds are the sounds heard through a stethoscope when blood vessels collapse under the pressure of a blood cuff during blood pressure measurement. They are widely used in non-invasive blood pressure measurement. Korotkoff sounds originate from the vibrations of blood vessels and therefore necessarily contain information about vascular stiffness. Furthermore, ease of use, portability, and intelligence are the main themes of today, and there is a huge demand for early screening for cardiovascular disease.

[0045] In an exemplary embodiment, a wrist-type blood vessel hardness tester is provided, such as Figures 1-4As shown, the wrist-type vascular hardness tester includes: a wristband 2, an airbag 21, a vibration sensor 22, a pressure sensor 11 and a detection box 1. The airbag 21, the vibration sensor 22 and the detection box 1 are all arranged on the wristband 2; the pressure sensor 11 is arranged at the bottom of the detection box 1. An air pump 15, an air valve 16 and a main board 13 are provided in the detection box 1; the air pump 15 is connected to the airbag 21 through the air valve 16; the vibration sensor 22 and the pressure sensor 11 are both connected to the main board 13, and the main board 13 is also connected to the control end of the air pump 15 and the control end of the air valve 16; when in use, the wristband 2 is wrapped around the user's wrist, the airbag 21 and the vibration sensor 22 are both located between the wristband 2 and the user's wrist, and the pressure sensor 11 is located between the detection box 1 and the user's wrist; the vibration sensor 22 is used to collect the user's blood vessel vibration signal and send the blood vessel vibration signal to the main board 13, and the pressure sensor 11 is used to detect the pressure signal and send the pressure signal to the main board 13; the main board 13 is used to control the air valve 16 and the air pump 15 to inflate and deflate the airbag 21 based on the blood vessel vibration signal and / or pressure signal, and extract the blood vessel vibration signal of the target time period, and calculate the blood vessel hardness based on the signal. The target time period is the deflation time period, that is, the time period between the complete collapse of the blood vessel and the complete recovery of the blood vessel.

[0046] The vascular sclerosis detector provided in this application can be worn on the wrist by using the wristband 2. The airbag 21 compresses the blood vessels during inflation and deflation, and the vibration sensor 22 captures the vascular vibration signal emitted by the radial artery. By processing and extracting the characteristics of this vascular vibration signal, the degree of vascular sclerosis in the human body can be detected. The main board 13 issues instructions to the air pump 15 and the air valve 16 to control the air pump 15 to inflate and deflate the airbag 21. The specific steps include the following:

[0047] When a blood vessel hardness detection instruction is received, the air valve 16 and the air pump 15 are controlled to inflate the airbag 21; during the inflation process, within a preset time period after the blood vessel vibration signal and / or the pressure signal indicate that the blood vessel is completely collapsed, the air valve 16 and the air pump 15 are controlled to deflate the airbag 21; during the deflation process, when the blood vessel vibration signal and / or the pressure signal indicate that the blood vessel is completely recovered, the air valve 16 and the air pump 15 are controlled to stop deflating the airbag 21.

[0048] Collapse is a process. From the beginning to complete collapse, a vibration signal is present, but it disappears after complete collapse. Conversely, a signal is present throughout the recovery process, but disappears after complete recovery. Therefore, the presence or absence of a vibration signal can be used to determine complete collapse and recovery. Furthermore, the complete collapse and recovery of a blood vessel can also be reflected in the pressure signal, so this can also be used to determine the complete collapse and recovery states.

[0049] In the embodiments of the present application, the complete collapse of the blood vessel is determined by detecting whether the blood vessel vibration signal changes from being present to being absent, or by detecting whether the amplitude of the pressure signal is greater than a certain threshold. The complete recovery of the blood vessel is determined by detecting whether the blood vessel vibration signal changes from being present to being absent again, or by detecting whether the amplitude of the pressure signal is less than a certain threshold. Generally, the blood vessel is considered to have fully recovered when the airbag 21 is deflated or the internal and external pressures of the airbag 21 are equal.

[0050] In another exemplary embodiment, the mainboard 13 is further configured to obtain the wristband pressure when the blood vessel is completely collapsed and completely recovered, ie, the first wristband pressure and the second wristband pressure, through the pressure sensor 11, and store and calculate the pressure.

[0051] In another exemplary embodiment, the above-mentioned wrist-type vascular hardness tester also includes a motor vibrator 136, the control end of which is connected to the main board 13. The motor vibrator 136 is used to utilize the electromagnetic induction effect to generate a magnetic field generated by the current to drive the rotor to rotate and generate vibration, which is used for abnormal vibration prompts.

[0052] In another exemplary embodiment, the wrist-type vascular hardness tester further includes an accelerometer connected to the mainboard 13 . The accelerometer is used to identify the wearer's motion state and ensure that the wearer is in a resting state during the measurement process.

[0053] In another exemplary embodiment, a battery 14 is further provided in the detection box 1 for powering the device, and a computing module, a Bluetooth module 131, a power management module 135, a touch chip 137, a storage module and a display module are provided on the main board 13.

[0054] Among them, the Bluetooth module 131 is used for data transmission to realize the PC-side display of the first wristband pressure, the second wristband pressure and the blood vessel vibration signal, as well as the APP-side display. The operation module is used for processing, calculating and controlling the signals collected by the above-mentioned pressure sensor 11 and vibration sensor 22. The storage module includes two parts: running memory 133 and flash memory 134, which are used to store data. The power management module 135 is used to manage the power supply and power control of the chip. Low power consumption operation is achieved, battery life is extended, and system stability and reliability are improved. The touch chip 137 is used for touch screen operation of the device. Instructions are passed to the operation module through touch, and the operation module operates according to the above instructions. The display module is used to display the results of each function.

[0055] In another exemplary embodiment, the computation module is implemented based on a digital signal processor 132. The blood vessel vibration signal acquired by the vibration sensor 22 is collected by a 24-bit analog-to-digital conversion module within the digital signal processor 132 at a frequency of 1000 Hz. The sampled data is then transmitted to a storage module for access by the digital signal processor 132, which then processes and computes the data.

[0056] The processing performed by the digital signal processor 132 includes but is not limited to detrending, denoising, and smoothing the blood vessel oscillation signal, thereby improving the signal-to-noise ratio of the signal and the accuracy of the calculation.

[0057] The calculation performed by the digital signal processor 132 is to calculate vascular stiffness using the target time-frequency domain features of the vascular oscillation signal. These target time-frequency domain features are those that are significantly correlated with vascular stiffness, including but not limited to the absolute maximum amplitude, center of mass, skewness, waveform indices, center of gravity frequency, frequency corresponding to the maximum power value, natural frequency, and average frequency of the vascular oscillation signal. Finally, the time-frequency domain features of the vascular oscillation signal during the target time period, such as the absolute maximum amplitude, center of mass, skewness, waveform indices, center of gravity frequency, frequency corresponding to the maximum power value, natural frequency, and average frequency, are converted into vascular stiffness.

[0058] In another exemplary embodiment, the vascular hardness is calculated by constructing a vascular hardness calculation model, and the vascular hardness calculation model can be any model such as a neural network model and a linear regression model.

[0059] In another exemplary embodiment, the blood vessel hardness is obtained by the following steps:

[0060] The time-frequency domain features of each target are normalized and dimensionless.

[0061] According to the correlation between each target time-frequency domain feature and vascular hardness, each target time-frequency domain feature is weighted.

[0062] According to the weight of each target time-frequency domain feature, each target time-frequency domain feature is integrated into a new hardening index indicator, namely vascular hardness.

[0063] The blood vessel hardness obtained by the above calculation method is displayed by the display module and stored in the storage module for subsequent output to the PC or APP.

[0064] In another exemplary embodiment, a centroid calculation method is proposed. In this embodiment, the centroid takes into account both the maximum amplitude and the location where the maximum amplitude occurs, which can more comprehensively reflect the characteristics of the blood vessel vibration signal. The blood vessel vibration signal is framed and processed, with half of the total number of frames n as the origin, that is, with the first frame as the origin. Frame or The position of the frame blood vessel vibration signal is taken as the origin, and a new coordinate axis is established, which is the target coordinate system. The coordinates of each frame blood vessel vibration signal in the target coordinate system are: , and at the same time, the maximum amplitude of each frame of blood vessel vibration signal is calculated, which are Then, the coordinates and maximum amplitude of the blood vessel vibration signal of each frame are weighted and summed, and the result is divided by the sum of the maximum amplitudes to obtain the centroid. The formula is as follows.

[0065] .

[0066] in, is the center of mass, 、 、 are the coordinates of the 1st, 2nd and nth frames of the blood vessel vibration signal in the target coordinate system, respectively. The target coordinate system is a coordinate system established according to the positions of the blood vessel vibration signals in each frame. 、 and are the maximum amplitudes of the blood vessel vibration signal in the 1st frame, the 2nd frame, and the nth frame respectively, and n is the number of frames of the blood vessel vibration signal in the target time period.

[0067] In another exemplary embodiment, the digital signal processor 132 also provides calculations of blood pressure and heart rate based on the blood vessel oscillation signal, which are also displayed by the display module and stored in the storage module for subsequent output to the PC or APP.

[0068] In another exemplary embodiment, the mainboard 13 is equipped with a Bluetooth module 131, which transmits the calculation results of the digital signal processor 132, as well as data stored in the running memory 133 and flash memory 134, to a PC or app. Under the control of the digital signal processor 132, the vibration sensor 22 and pressure sensor 11 acquire signals in real time, store them in the flash memory 134, and then process and calculate them through the digital signal processor 132. The power management module 135 effectively distributes power to various components to ensure normal operation and optimized performance of the device. The motor vibrator 136 uses electromagnetic induction to generate a magnetic field generated by the current, driving the rotor to rotate and vibrate. When the measurement results are abnormal, a vibration prompt is provided to the tester. Furthermore, the touch chip 137 provides touchscreen operation for all functions. Touch commands are transmitted to the digital signal processor 132, which issues functional instructions and performs further calculations. The touch chip 137 facilitates the application of the vascular hardness tester in various scenarios and improves the user experience.

[0069] In another exemplary embodiment, the aforementioned wrist-type vascular hardness tester can be further expanded with a 3D step-counting sensor 12 incorporated into the test box 1. When worn while walking or exercising, the device can simultaneously measure steps, mileage, and calories burned, aiding fitness. Of course, the wrist-type vascular hardness tester can also be expanded with other functions, such as blood oxygen monitoring, blood sugar monitoring, electrocardiogram monitoring, sleepiness monitoring, location navigation, and time display.

[0070] In another exemplary embodiment, referring to Figure 5 In this example, vascular vibration signals were collected from both the vascular sclerosis group and the control group. The signals were then subjected to baseline drift removal and filtering to improve the signal-to-noise ratio and enhance the accuracy of the results. The detrend function was used to eliminate the DC component and linear trend terms. A wavelet transform was used for denoising. Based on the principle that the strength of the useful signal is evenly distributed across each layer, while the noise intensity decreases with increasing decomposition layers, different thresholds were set for each layer of wavelet coefficients. Finally, the proposed new threshold function was used for wavelet analysis.

[0071] Threshold denoising.

[0072] In another exemplary embodiment, referring to Figure 6 , extract the time-frequency domain features of the preprocessed signal, including but not limited to the maximum amplitude, centroid, natural frequency and average frequency. Figure 6 The statistical results of the natural frequency are shown, which show that vascular sclerosis can be identified through typical time-frequency domain characteristics.

[0073] Other signal processing methods or time-frequency domain characteristics of blood vessel vibration signals can also be selected. The embodiments of the present application only provide a feasible solution and cannot limit the scope of protection of the present application.

[0074] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A wrist-type vascular hardness tester, characterized in that: The wrist-type vascular hardness tester includes: a wristband, an airbag, a pressure sensor, a vibration sensor and a detection box, wherein the airbag, the vibration sensor and the detection box are all arranged on the wristband; the pressure sensor is arranged at the bottom of the detection box; The detection box is provided with an air pump, an air valve and a main board; the air pump is connected to the air bag through the air valve; The vibration sensor and the pressure sensor are both connected to the main board, and the main board is also connected to the control end of the air pump and the control end of the air valve; When in use, the wristband is wrapped around the user's wrist, the airbag and the vibration sensor are located between the wristband and the user's wrist, and the pressure sensor is located between the detection box and the user's wrist; the vibration sensor is used to collect the user's blood vessel vibration signal and send the blood vessel vibration signal to the mainboard, and the pressure sensor is used to detect the pressure signal and send the pressure signal to the mainboard; The main board is used to control the air valve and the air pump to inflate and deflate the airbag according to the blood vessel vibration signal and / or the pressure signal, and to extract the blood vessel vibration signal of a target time period, and calculate the blood vessel hardness according to the blood vessel vibration signal of the target time period. The target time period is the deflation time period, that is, the time period between the complete collapse of the blood vessel and the complete recovery of the blood vessel.

2. The wrist-type vascular hardness tester according to claim 1, characterized in that: In terms of controlling the air valve and the air pump to inflate and deflate the airbag based on the blood vessel vibration signal, the mainboard is specifically used to: When receiving a blood vessel hardness detection instruction, controlling the air valve and the air pump to inflate the airbag; During the inflation process, within a preset time period after the blood vessel vibration signal and / or the pressure signal indicate that the blood vessel has completely collapsed, controlling the air valve and the air pump to deflate the airbag; During the deflation process, when the blood vessel vibration signal and / or the pressure signal indicates that the blood vessel has fully recovered, the air valve and the air pump are controlled to stop deflation of the airbag.

3. The wrist-type vascular hardness tester according to claim 1, characterized in that: In terms of calculating blood vessel hardness based on the blood vessel vibration signal during the target time period, the main board is specifically configured to: Extracting target time-frequency domain features of the vascular oscillation signal in a target time period; the target time-frequency domain features are time series features that are significantly correlated with vascular hardness; The vascular hardness is calculated using a vascular hardness calculation model according to the target time-frequency domain characteristics; the vascular hardness calculation model characterizes the relationship between the target time-frequency domain characteristics and the vascular hardness.

4. The wrist-type vascular hardness tester according to claim 3, characterized in that: Extracting the target time-frequency domain features of the vascular oscillation signal in the target time period, which previously also includes: Detrending, denoising and smoothing are performed on the blood vessel vibration signal.

5. The wrist-type blood vessel hardness tester according to claim 3, characterized in that: The target time-frequency domain features include: one or more of: absolute maximum amplitude, center of mass, skewness, waveform index, center of gravity frequency, frequency corresponding to maximum power value, natural frequency and average frequency.

6. The wrist-type blood vessel hardness tester according to claim 5, characterized in that: The calculation formula of the centroid is: ； in, is the center of mass, 、 、 are the coordinates of the 1st, 2nd and nth frames of the blood vessel vibration signal in the target coordinate system, respectively. The target coordinate system is a coordinate system established according to the positions of the blood vessel vibration signals in each frame. 、 and are the maximum amplitudes of the blood vessel vibration signal in the 1st frame, the 2nd frame, and the nth frame respectively, and n is the number of frames of the blood vessel vibration signal in the target time period.

7. The wrist-type blood vessel hardness tester according to claim 1, characterized in that: The wrist-type vascular hardness tester further includes: a 3D sensor for step counting; The 3D pedometer sensor is disposed in the detection box, and the 3D pedometer sensor is connected to the mainboard. The mainboard is further configured to measure the number of steps according to the detection signal of the 3D pedometer sensor. The main board is also used to obtain the pressure signal detected by the pressure sensor as the first wristband pressure when the blood vessel vibration signal or pressure signal indicates that the blood vessel has collapsed; and to obtain the pressure signal detected by the pressure sensor as the second wristband pressure when the blood vessel vibration signal or pressure signal indicates that the blood vessel has fully recovered.

8. The wrist-type blood vessel hardness tester according to claim 1, characterized in that: The wrist-type vascular hardness tester also includes: an accelerometer, which is arranged in the detection box and connected to the main board. The main board is also used to identify the user's movement state based on the acceleration signal detected by the accelerometer to ensure that the user is in a resting state during the measurement process.

9. The wrist-type blood vessel hardness tester according to claim 1, characterized in that: The wrist-type vascular hardness tester also includes: a motor vibrator, which is arranged in the detection box. The control end of the motor vibrator is connected to the main board. The main board is also used to control the motor vibrator to vibrate when the vascular hardness meets the warning conditions.

10. The wrist-type blood vessel hardness tester according to claim 1, characterized in that: The mainboard includes: a computing module, a Bluetooth module, a power management module, a touch chip, a storage module and a display module; The Bluetooth module, the touch chip, the storage module and the display module are all connected to the computing module; The power management module is connected to the computing module, the Bluetooth module, the touch chip, the storage module and the display module respectively.

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