Driver electrocardiogram detection device and effective electrocardiogram signal extraction method

Abstract

The invention discloses a driver electrocardio detection device and an effective electrocardio signal extraction method, and relates to the field of health management.The driver electrocardio detection device comprises a left-hand electrode, a right-hand electrode, a reference electrode, an electrocardio collection circuit and a microprocessor circuit, and the electrocardio collection circuit is used for collecting electrocardio signals; the microprocessor circuit is used for extracting effective electrocardiosignals in the electrocardiosignals; wherein the left-hand electrode and the right-hand electrode are arranged on the top surface of the steering wheel, and the reference electrode is distributed on the bottom surface of the steering wheel, so that a driver does not need to wear, electrocardiosignal detection can be realized under the condition that the driver holds the steering wheel, and extra operation is not needed; and the reference electrode is arranged, so that the common-mode rejection capability of the electrocardio acquisition circuit is improved, the anti-interference capability of the driver electrocardio detection device is further improved, and on the basis that the comfort of a driver is not affected, electrocardio monitoring is carried out while driving is carried out.

Description

Technical Field

[0001] The present application relates to the field of health management, and in particular to a driver electrocardiogram (ECG) detection device and an effective ECG signal extraction method. Background Art

[0002] As the global population ages, the incidence of heart disease among the elderly has increased significantly, and the demand for long-term health monitoring has risen sharply. Heart disease, due to its sporadic and hidden nature, is often difficult to detect in the early stages. Long-term ECG monitoring has become an important means of predicting and diagnosing these diseases.

[0003] At present, cars have become an indispensable means of transportation, and people drive an average of about one hour a day. At the same time, the automotive industry is rapidly transforming towards intelligence and automation, and integrating health monitoring functions into cars has become an important direction of technological innovation.

[0004] ECG monitoring and disease identification while driving requires solving problems such as noise interference and vibration interference in the vehicle environment, and it is necessary to consider the comfort and convenience of wearing electrodes. The wearing of ECG electrodes should not bring additional wearing burden to the driver and should not affect normal driving. Summary of the invention

[0005] The purpose of this application is to provide a driver ECG detection device and an effective ECG signal extraction method, which can realize ECG monitoring while driving without affecting the driver's comfort.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a driver's electrocardiogram detection device, the driver's electrocardiogram detection device comprising: a left-hand electrode, a right-hand electrode, a reference electrode, an electrocardiogram acquisition circuit, and a microprocessor circuit;

[0008] The left-hand electrode and the right-hand electrode are arranged on the top surface of the steering wheel, wherein the left-hand electrode and the right-hand electrode are respectively distributed on the left half and the right half of the steering wheel when the steering wheel is not rotated;

[0009] The reference electrodes are distributed on the bottom surface of the steering wheel;

[0010] The left-hand electrode, the right-hand electrode and the reference electrode are all connected to the ECG acquisition circuit; the ECG acquisition circuit is connected to the microprocessor circuit;

[0011] The ECG acquisition circuit is used for acquiring ECG signals; and the microprocessor circuit is used for extracting effective ECG signals from the ECG signals.

[0012] Optionally, in terms of extracting effective ECG signals from ECG signals, the microprocessor circuit is specifically used for:

[0013] The quality index of the ECG signal per unit time period is calculated using the following formula;

[0014]

[0015] Where bSQI is the quality index of the ECG signal in a unit time period, N pan is the number of R peaks in the ECG signal per unit time period calculated using the Pan-Tompkins algorithm, N FindPeaks is the number of R peaks in the ECG signal per unit time period calculated using the sliding window and threshold analysis method;

[0016] When the quality index of the electrocardiogram signal in the unit time period is greater than the quality index threshold, determining that the electrocardiogram signal in the unit time period is a valid electrocardiogram signal;

[0017] When the quality index of the electrocardiogram signal in the unit time period is not greater than the quality index threshold, it is determined that the electrocardiogram signal in the unit time period is not a valid electrocardiogram signal.

[0018] Optionally, the ECG acquisition circuit includes an ECG front-end detection circuit, a high-pass filter circuit, a low-pass filter circuit, a signal amplification circuit and a trap circuit which are connected in sequence.

[0019] Optionally, the ECG front-end detection circuit uses a KS1081 chip;

[0020] The input pins INP1 and INN1 of the KS1081 chip are connected to the left-hand electrode and the right-hand electrode respectively, and the reference pin RLD of the KS1081 chip is connected to the reference electrode;

[0021] The output pins VO1 and VO2 of the KS1081 chip are connected to the high-pass filter circuit;

[0022] The lead status pin SDO of the KS1081 chip is connected to the microprocessor circuit;

[0023] The ECG acquisition circuit is also used to determine whether to acquire ECG signals according to the state of the lead state pin SDO of the KS1081 chip.

[0024] Optionally, the high-pass filter circuit is a voltage-controlled voltage source type second-order high-pass filter circuit, the low-pass filter circuit is a voltage-controlled voltage source type second-order low-pass filter circuit, the signal amplification circuit is a common-phase signal amplification circuit, and the trap circuit is a double-T active trap circuit.

[0025] Optionally, the driver's electrocardiogram detection device further includes: a gyroscope circuit;

[0026] The gyroscope circuit is arranged at the center of the steering wheel, the gyroscope circuit is connected to the microprocessor circuit, and the gyroscope circuit is used to collect the three-dimensional angular velocity of the steering wheel;

[0027] The microprocessor circuit is also used to calculate the steering wheel motion amplitude according to the three-dimensional angular velocity of the steering wheel using the following formula; when the steering wheel motion amplitude is less than the amplitude threshold, it is determined that the condition for extracting the valid electrocardiogram signal from the electrocardiogram signal is met; when the steering wheel motion amplitude is not less than the amplitude threshold, it is determined that the condition for extracting the valid electrocardiogram signal from the electrocardiogram signal is not met;

[0028]

[0029] Among them, A is the steering wheel movement amplitude, ax, ay and az are the three-dimensional angular velocities of the steering wheel.

[0030] Optionally, the driver ECG detection device further includes a Bluetooth communication circuit, and the Bluetooth communication circuit is connected to the ECG acquisition circuit.

[0031] In a second aspect, the present application provides a method for extracting an effective electrocardiogram signal, and the method for extracting an effective electrocardiogram signal is applied to the above-mentioned driver electrocardiogram detection device;

[0032] The effective electrocardiogram signal extraction method comprises:

[0033] Obtaining ECG signals in a unit time period;

[0034] The Pan-Tompkins algorithm is used to calculate the number of R peaks in the electrocardiogram signal in a unit time period as the first R peak number;

[0035] The number of R peaks in the ECG signal per unit time period is calculated using a sliding window and threshold analysis method as the second R peak number;

[0036] Calculating the quality index of the electrocardiogram signal in a unit time period according to the number of the first R peaks and the number of the second R peaks;

[0037] When the quality index of the electrocardiogram signal in the unit time period is greater than the quality index threshold, determining that the electrocardiogram signal in the unit time period is a valid electrocardiogram signal;

[0038] When the quality index of the electrocardiogram signal in the unit time period is not greater than the quality index threshold, it is determined that the electrocardiogram signal in the unit time period is not a valid electrocardiogram signal.

[0039] Optionally, obtaining the electrocardiogram signal in a unit time period also includes:

[0040] Get the status of the lead status pin SDO of the KS1081 chip;

[0041] When the state of the lead status pin SDO of the KS1081 chip is at a low level, return to the step of obtaining the state of the lead status pin SDO of the KS1081 chip;

[0042] When the state of the lead status pin SDO of the KS1081 chip is high, perform the following steps:

[0043] Get the three-dimensional angular velocity of the steering wheel;

[0044] According to the three-dimensional angular velocity of the steering wheel, the steering wheel movement amplitude is calculated using the following formula;

[0045]

[0046] Among them, A is the steering wheel movement amplitude, ax, ay and az are the three-dimensional angular velocities of the steering wheel;

[0047] When the steering wheel movement amplitude is less than the amplitude threshold, executing the step of acquiring the electrocardiogram signal of the unit time period;

[0048] When the steering wheel movement amplitude is not less than the amplitude threshold, return to the step of obtaining the three-dimensional angular velocity of the steering wheel.

[0049] Optionally, a Pan-Tompkins algorithm is used to calculate the number of R peaks in the electrocardiogram signal in a unit time period as the first number of R peaks, and the method also includes:

[0050] The signal-to-noise ratio of the ECG signal per unit time period is calculated using the following formula;

[0051]

[0052] Among them, SNR (dB) is the signal-to-noise ratio of the ECG signal per unit time period, P signal and P noise are the signal power and noise power in the ECG signal per unit time period respectively;

[0053] Determine whether the signal-to-noise ratio of the electrocardiogram signal in a unit time period is greater than a signal-to-noise ratio threshold, and obtain a first determination result;

[0054] If the first judgment result is no, then return to the step of "obtaining the ECG signal of a unit time period";

[0055] If the first judgment result is yes, the step of "using the Pan-Tompkins algorithm to calculate the number of R peaks in the electrocardiographic signal per unit time period as the first number of R peaks" is executed.

[0056] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0057] The present application provides a driver's ECG detection device and an effective ECG signal extraction method, wherein the driver's ECG detection device comprises: a left-hand electrode, a right-hand electrode, a reference electrode, an ECG acquisition circuit and a microprocessor circuit; wherein the left-hand electrode and the right-hand electrode are arranged on the top surface of a steering wheel, and the reference electrode is distributed on the bottom surface of the steering wheel, and the driver does not need to wear them, and the driver can realize ECG signal detection only when holding the steering wheel, without additional operation, and the provision of the reference electrode helps to increase the common-mode suppression capability of the ECG acquisition circuit, thereby improving the anti-interference capability of the driver's ECG detection device. The present application realizes ECG monitoring while driving without affecting the driver's comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 paying creative work.

[0059] Figure 1 A schematic diagram of the structure of a driver's electrocardiogram detection device provided in one embodiment of the present application;

[0060] Figure 2 A schematic diagram of the arrangement of ECG electrodes provided in one embodiment of the present application;

[0061] Figure 3 A schematic diagram of the structure of an ECG acquisition circuit provided in one embodiment of the present application;

[0062] Figure 4 A pin diagram of the KS1081 chip provided in one embodiment of the present application;

[0063] Figure 5 A flowchart of an effective electrocardiogram signal extraction method provided in one embodiment of the present application;

[0064] Figure 6 A schematic diagram of an effective electrocardiogram signal extraction method provided in an embodiment of the present application;

[0065] Figure 7 This is a diagram of a driver's electrocardiogram (ECG) waveform actually measured in one embodiment of the present application. DETAILED DESCRIPTION

[0066] 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 only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0067] In order to make the above-mentioned objects, 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.

[0068] In an exemplary embodiment, Figure 1 As shown, a driver electrocardiogram detection device is provided, including: a left-hand electrode, a right-hand electrode, a reference electrode, an electrocardiogram acquisition circuit and a microprocessor circuit.

[0069] The left-hand electrode and the right-hand electrode are arranged on the top surface of the steering wheel, wherein the left-hand electrode and the right-hand electrode are respectively distributed on the left and right halves of the steering wheel when it is not turned; the reference electrode is distributed on the bottom surface of the steering wheel. The left-hand electrode, the right-hand electrode and the reference electrode are metal dry electrodes made of silver foil with a thickness of 0.2 to 1 mm. The silver foil metal electrode (i.e., the metal dry electrode made of silver foil) has the characteristics of good stability, strong conductivity and corrosion resistance, and is more suitable for use as an electrode for electrocardiogram detection. Figure 2 As shown, the left-hand electrode corresponds to Figure 2 The LA electrode and the right hand electrode correspond to Figure 2 The RA electrode and the reference electrode correspond to Figure 2 The RL electrode, LA electrode and RA electrode are semi-circular and are respectively placed on the left and right sides of the top of the steering wheel, and the RL electrode is a ring electrode and is placed at the bottom of the steering wheel.

[0070] As a preferred embodiment, Figure 1 As shown, the driver ECG detection device in this embodiment also includes: a gyroscope circuit and a Bluetooth communication circuit. The gyroscope circuit, the Bluetooth communication circuit, the ECG acquisition circuit and the microprocessor circuit are placed inside the steering wheel as an electronic system. Figure 1 As shown, the electronic system is electrically connected to three electrodes (left hand electrode, right hand electrode, reference electrode). The ECG acquisition circuit, gyroscope circuit, and Bluetooth communication circuit are all connected to and controlled by the microprocessor circuit. The microprocessor circuit can pick up and condition the driver's ECG signal through the ECG acquisition circuit, obtain the steering wheel rotation data (i.e., three-dimensional angular velocity) through the gyroscope circuit, and transmit the ECG data wirelessly through the Bluetooth communication circuit.

[0071] like Figure 3As shown, the ECG acquisition circuit includes: ECG front-end detection circuit, high-pass filter circuit, low-pass filter circuit, signal amplification circuit and trap circuit. The ECG acquisition circuit is connected to the electrode through the input interface and connected to the microcontroller circuit through the output interface. The ECG front-end detection circuit is composed of the KS1081 chip application circuit. The ECG front-end detection circuit is connected to the input interface, and its lead status pin is connected to the output interface; the ECG front-end detection circuit is connected to the high-pass filter circuit, which is a voltage-controlled voltage source type 2nd order high-pass filter circuit, and the high-pass filter cutoff frequency is 0.5Hz; the high-pass filter circuit is connected to the low-pass filter circuit, which is a voltage-controlled voltage source type 2nd order low-pass filter circuit, and the low-pass filter cutoff frequency is 35Hz; the low-pass filter circuit is connected to the voltage amplifier circuit, which is a common-phase signal amplifier circuit with an amplification factor of 4 times; the voltage amplifier circuit is connected to the trap circuit, which is a double-T active trap circuit with a trap center frequency of 50Hz, and the trap circuit is connected to the output ECG signal and the output interface.

[0072] like Figure 4 As shown, the input pins INP1 and INN1 of the KS1081 chip are connected to the left-hand electrode and the right-hand electrode respectively, the reference pin RLD of the KS1081 chip is connected to the reference electrode; the output pins VO1 and VO2 of the KS1081 chip are connected to the high-pass filter circuit; the lead status pin SDO of the KS1081 chip is connected to the microprocessor circuit.

[0073] In another exemplary embodiment of the present application, an effective ECG extraction method is provided, which can be deployed and implemented on the driver ECG detection device proposed above. Figure 5 As shown, the method includes:

[0074] Step 501, obtaining an electrocardiogram signal in a unit time period.

[0075] Step 502: Use the Pan-Tompkins algorithm to calculate the number of R peaks in the electrocardiogram signal in a unit time period as the first number of R peaks.

[0076] Step 503: Use a sliding window and threshold analysis method to calculate the number of R peaks in the electrocardiogram signal in a unit time period as the second number of R peaks.

[0077] Step 504: Calculate the quality index of the ECG signal in a unit time period according to the first R peak number and the second R peak number.

[0078] Step 505 : when the quality index of the ECG signal in the unit time period is greater than the quality index threshold, determining that the ECG signal in the unit time period is a valid ECG signal.

[0079] Step 506: When the quality index of the ECG signal in the unit time period is not greater than the quality index threshold, it is determined that the ECG signal in the unit time period is not a valid ECG signal.

[0080] In the vehicle environment, the left-hand electrode, right-hand electrode and reference electrode are deployed on the steering wheel. The detection conditions are met only when the driver holds the steering wheel electrodes with both hands. Due to the use of metal dry electrodes, the movement of the driver's hands on the steering wheel is more likely to produce motion artifacts, which will submerge the ECG signal. Therefore, only when the driver drives with both hands and does not operate the steering wheel drastically, it is possible to collect effective ECG signals.

[0081] Based on the above considerations, the effective ECG extraction method in this embodiment sets the conditions for ECG signal extraction, such as Figure 6 As shown, at this time, the above method can be implemented through the following steps.

[0082] Step 601, clearing the data in the ECG data storage area.

[0083] Step 602, reading the level of the lead status pin of the ECG acquisition circuit.

[0084] Step 603, when the driver puts both hands on the steering wheel electrodes, it is in the lead connection state, and the corresponding lead state pin is high level. When the driver puts one hand on the steering wheel electrode, or does not put it on the steering wheel electrode, it is in the lead detachment state, and the lead state pin is low level. When the lead state pin is high level, it means that the driver has both hands holding the steering wheel electrodes, and the angular velocity data of the gyroscope circuit can continue to be read. Otherwise, return to step 601 for execution.

[0085] Step 604, read the angular velocity values ​​in three directions output by the gyroscope circuit, recorded as ax, ay, az.

[0086] Step 605, the steering wheel movement amplitude A is calculated according to the formula:

[0087]

[0088] When the rotation amplitude A is less than the threshold value F, which is the maximum steering wheel rotation angular velocity amplitude when a valid ECG signal can be extracted, it is considered that the driver's steering wheel operation or the vibration noise from the vehicle body and the road bump interference can be ignored, and the ECG signal sampling and storage can continue. Otherwise, return to step 601 to execute.

[0089] Step 605, according to the angular velocity values ​​in three directions output by the gyroscope circuit, recorded as ax, ay, az, according to the formula:

[0090]

[0091] Calculate the amplitude A. When A is less than the threshold F, which is the maximum steering wheel movement amplitude when a valid ECG signal can be extracted, it is considered that the driver's steering wheel operation or the vibration noise from the vehicle body and the road bump interference can be ignored. The ECG signal sampling and storage can continue. Otherwise, return to step 601 and execute again.

[0092] Step 606, sampling and storing the ECG data.

[0093] Step 607, when ECG signals are usually used for disease identification, the data length is usually 10 seconds. Therefore, when the continuously collected ECG signals reach 10 seconds, the signal-to-noise ratio (SNR) and ECG signal quality index (bSQI) can be calculated to measure whether the signal is valid. If it is less than 10 seconds, it is necessary to return to step 602 for execution.

[0094] The signal-to-noise ratio (SNR) is calculated as:

[0095]

[0096] Where P signal and P noise Represent signal power and noise power respectively, and the signal-to-noise ratio is in decibels (dB). A signal-to-noise ratio of 30dB means that the signal power is 1000 times the noise power. When the signal-to-noise ratio is less than 30dB, return to step 601 for execution. When the signal-to-noise ratio is greater than 30dB, it is considered that the signal quality is high, and the calculation of the ECG signal quality index (bSQI) continues.

[0097] The calculation method of ECG signal quality index (bSQI) is:

[0098]

[0099] Where N pan is the number of R peaks in the ECG data calculated using the Pan-Tompkins algorithm, N FindPeaks The number of R peaks in the ECG data calculated by the sliding window and threshold analysis methods is divided by the number of R peaks calculated by the two methods to obtain the ECG signal quality index (bSQI). When the bSQI is greater than 0.9, it is considered that the signal consistency is good and the quality is high, and the 10 seconds of valid ECG are wirelessly transmitted through the Bluetooth communication circuit, otherwise, return to step 601 for execution.

[0100] 10. Transmit 10 seconds of ECG data via Bluetooth communication circuit.

[0101] According to the method of the present invention, when the driver holds the steering wheel electrodes with both hands and drives straight in good road conditions, the actual ECG signal effect extracted is as follows: Figure 7 As shown, five characteristic waveforms of the ECG signal, namely, P wave, Q wave, R wave, S wave and T wave, can be clearly observed, which illustrates the effectiveness of the hardware device and algorithm proposed in the present invention.

[0102] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0103] 1. Steering wheel electrode part: Traditional single-lead ECG detection equipment only uses two electrodes. The present invention adds a reference electrode. The reference electrode has a larger area and covers the lower side of the steering wheel, which is convenient for the driver to grip. The reference electrode helps to increase the common-mode suppression capability of the ECG acquisition circuit and can improve the circuit's anti-interference ability.

[0104] 2. ECG acquisition circuit: Based on the integrated chip KS1081, the ECG front-end detection circuit can be directly connected to three ECG electrodes. It has high integration and can reduce the circuit size. The chip has a lead-off detection function, which is convenient for detecting whether the driver holds the steering wheel with both hands. The ECG signal is further processed using a high-pass filter circuit, a low-pass filter circuit, a voltage amplifier circuit, and a notch circuit, so that the ECG signal obtained from the hardware is of high quality.

[0105] 3. Electronic system part: By introducing the gyroscope circuit and using the software algorithm to extract the rotation threshold, it is possible to determine whether the driver is turning the steering wheel based on the threshold setting. It is meaningless to collect ECG data while turning the steering wheel. Such processing can avoid the consumption and waste of computing resources.

[0106] 4. Effective ECG detection algorithm: Combined with the electronic system circuit, the driver's steering wheel holding state and the driver's steering wheel operation state are detected, and the algorithm is used to calculate the quality of the collected ECG signal to ensure that only valid ECG signals of 10 seconds are transmitted wirelessly, which saves computing resources and is energy-efficient and environmentally friendly. It also provides a preliminary foundation and a reliable data source for subsequent disease identification, fatigue detection, and emotion recognition.

[0107] The technical features of the above embodiments may 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.

[0108] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will 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 driver's electrocardiogram detection device, characterized in that: The driver's ECG detection device comprises: a left-hand electrode, a right-hand electrode, a reference electrode, an ECG acquisition circuit and a microprocessor circuit; The left-hand electrode and the right-hand electrode are arranged on the top surface of the steering wheel, wherein the left-hand electrode and the right-hand electrode are respectively distributed on the left half and the right half of the steering wheel when the steering wheel is not rotated; The reference electrodes are distributed on the bottom surface of the steering wheel; The left-hand electrode, the right-hand electrode and the reference electrode are all connected to the ECG acquisition circuit; the ECG acquisition circuit is connected to the microprocessor circuit; The ECG acquisition circuit is used for acquiring ECG signals; and the microprocessor circuit is used for extracting effective ECG signals from the ECG signals.

2. The driver electrocardiogram detection device according to claim 1, characterized in that: In terms of extracting effective ECG signals from ECG signals, the microprocessor circuit is specifically used for: The quality index of the ECG signal per unit time period is calculated using the following formula; Where bSQI is the quality index of the ECG signal in a unit time period, N pan is the number of R peaks in the ECG signal per unit time period calculated using the Pan-Tompkins algorithm, N FindPeaks is the number of R peaks in the ECG signal per unit time period calculated using the sliding window and threshold analysis method; When the quality index of the electrocardiogram signal in the unit time period is greater than the quality index threshold, determining that the electrocardiogram signal in the unit time period is a valid electrocardiogram signal; When the quality index of the electrocardiogram signal in the unit time period is not greater than the quality index threshold, it is determined that the electrocardiogram signal in the unit time period is not a valid electrocardiogram signal.

3. The driver electrocardiogram detection device according to claim 1, characterized in that: The ECG acquisition circuit comprises an ECG front-end detection circuit, a high-pass filter circuit, a low-pass filter circuit, a signal amplification circuit and a trap circuit which are connected in sequence.

4. The driver electrocardiogram detection device according to claim 3, characterized in that: The ECG front-end detection circuit adopts KS1081 chip; The input pins INP1 and INN1 of the KS1081 chip are connected to the left-hand electrode and the right-hand electrode respectively, and the reference pin RLD of the KS1081 chip is connected to the reference electrode; The output pins VO1 and VO2 of the KS1081 chip are connected to the high-pass filter circuit; The lead status pin SDO of the KS1081 chip is connected to the microprocessor circuit; The ECG acquisition circuit is also used to determine whether to acquire ECG signals according to the state of the lead state pin SDO of the KS1081 chip.

5. The driver electrocardiogram detection device according to claim 3, characterized in that: The high-pass filter circuit is a voltage-controlled voltage source type second-order high-pass filter circuit, the low-pass filter circuit is a voltage-controlled voltage source type second-order low-pass filter circuit, the signal amplification circuit is a common-phase signal amplification circuit, and the trap circuit is a double-T active trap circuit.

6. The driver electrocardiogram detection device according to claim 1, characterized in that: The driver's electrocardiogram detection device also includes: a gyroscope circuit; The gyroscope circuit is arranged at the center of the steering wheel, the gyroscope circuit is connected to the microprocessor circuit, and the gyroscope circuit is used to collect the three-dimensional angular velocity of the steering wheel; The microprocessor circuit is also used to calculate the steering wheel motion amplitude according to the three-dimensional angular velocity of the steering wheel using the following formula; when the steering wheel motion amplitude is less than the amplitude threshold, it is determined that the condition for extracting the valid electrocardiogram signal from the electrocardiogram signal is met; when the steering wheel motion amplitude is not less than the amplitude threshold, it is determined that the condition for extracting the valid electrocardiogram signal from the electrocardiogram signal is not met; Among them, A is the steering wheel movement amplitude, ax, ay and az are the three-dimensional angular velocities of the steering wheel.

7. The driver electrocardiogram detection device according to claim 1, characterized in that: The driver's ECG detection device also includes a Bluetooth communication circuit, which is connected to the ECG acquisition circuit.

8. A method for extracting effective electrocardiogram signals, characterized in that: The effective ECG signal extraction method is applied to the driver ECG detection device according to any one of claims 1 to 7; The effective electrocardiogram signal extraction method comprises: Obtaining ECG signals in a unit time period; The Pan-Tompkins algorithm is used to calculate the number of R peaks in the electrocardiogram signal in a unit time period as the first R peak number; The number of R peaks in the ECG signal per unit time period is calculated using a sliding window and threshold analysis method as the second R peak number; Calculating the quality index of the electrocardiogram signal in a unit time period according to the number of the first R peaks and the number of the second R peaks; When the quality index of the electrocardiogram signal in the unit time period is greater than the quality index threshold, determining that the electrocardiogram signal in the unit time period is a valid electrocardiogram signal; When the quality index of the electrocardiogram signal in the unit time period is not greater than the quality index threshold, it is determined that the electrocardiogram signal in the unit time period is not a valid electrocardiogram signal.

9. The effective electrocardiogram signal extraction method according to claim 8, characterized in that: Obtain the ECG signal of a unit time period, which also includes: Get the status of the lead status pin SDO of the KS1081 chip; When the state of the lead status pin SDO of the KS1081 chip is at a low level, return to the step of obtaining the state of the lead status pin SDO of the KS1081 chip; When the state of the lead status pin SDO of the KS1081 chip is high, perform the following steps: Get the three-dimensional angular velocity of the steering wheel; According to the three-dimensional angular velocity of the steering wheel, the steering wheel movement amplitude is calculated using the following formula; Among them, A is the steering wheel movement amplitude, ax, ay and az are the three-dimensional angular velocities of the steering wheel; When the steering wheel movement amplitude is less than the amplitude threshold, executing the step of acquiring the electrocardiogram signal of the unit time period; When the steering wheel movement amplitude is not less than the amplitude threshold, return to the step of obtaining the three-dimensional angular velocity of the steering wheel.

10. The effective electrocardiogram signal extraction method according to claim 8, characterized in that: The Pan-Tompkins algorithm is used to calculate the number of R peaks in the ECG signal per unit time period as the first R peak number, which also includes: The signal-to-noise ratio of the ECG signal per unit time period is calculated using the following formula; Among them, SNR (dB) is the signal-to-noise ratio of the ECG signal per unit time period, P signal and P noise are the signal power and noise power in the ECG signal per unit time period respectively; Determine whether the signal-to-noise ratio of the electrocardiogram signal in a unit time period is greater than a signal-to-noise ratio threshold, and obtain a first determination result; If the first judgment result is no, then return to the step of "obtaining the ECG signal of a unit time period"; If the first judgment result is yes, the step of "using the Pan-Tompkins algorithm to calculate the number of R peaks in the electrocardiogram signal per unit time period as the first R peak number" is executed.

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