CN103027675B - Novel portable three-lead real-time wireless electrocardiogram monitoring system and analyzing method - Google Patents

Abstract

The present invention provides a novel portable three-lead real-time wireless ECG monitoring system, which is mainly composed of an ECG acquisition electrode 1, an ECG acquisition module 2, a data processing module 3, a wireless module 4, a power supply module 5, and a console host computer 6 . The electrocardiogram acquisition electrode 1 picks up the weak electrocardiogram signal (usually a few mV) on the surface of the human body, and sends it to the electrocardiogram acquisition module 2. After processing such as amplification and filtering, the data processing module 3 performs sampling and digital signal processing, and then passes through The wireless module 4 is sent into the wireless network and finally sent to the console host computer 6. After the upper computer obtains the data, it uses the QRS complex wave detection algorithm to mark the Q, R, and S points and display them on the computer screen. Corresponding analysis methods are also provided. The invention solves the disadvantages that the existing electrocardiograph cannot monitor in real time, the cost of the existing real-time monitoring device is too high, and the existing electrocardiographic analysis algorithm is too complicated.

Description

New portable three-lead real-time wireless ECG monitoring system and analysis method

technical field

The invention relates to the collection and wireless transmission technology of ECG signal parameters in the field of human health monitoring, and includes a digital processing method for ECG signals, in particular to a novel portable three-lead real-time wireless ECG monitoring system and analysis method.

Background technique

As an important part of human vital signs, electrocardiogram has been widely used in various medical fields such as disease detection and patient monitoring. In the traditional field of disease diagnosis, doctors diagnose patients through the body surface standard 12-lead electrocardiogram, which is most common in cardiovascular diseases, such as arrhythmia and myocardial infarction. 24-hour ambulatory electrocardiogram is generally used in the intensive care unit to monitor the vital signs of critically ill patients in real time. However, these two electrocardiographs have their own weaknesses, for example, the traditional standard 12-lead electrocardiograph has a large volume and cannot be monitored in real time, and the Holter electrocardiograph used in the intensive care unit is expensive. Therefore, these two kinds of electrocardiographs are not suitable for common wards and personal families.

The bioelectrical changes of the heart itself are reflected on the surface of the body through the conductive tissue and body fluid around the heart, so that all parts of the body also undergo regular electrical changes in each cardiac cycle. The heart electrical change curve recorded by placing the measuring electrodes on a certain part of the human body surface is the electrocardiogram (expressed by ECG) that is currently routinely recorded clinically. The changes in the waveform curves in each cardiac cycle on the normal ECG are regular. Internationally, these waveforms are called P waves, QRS waves, and T waves, and sometimes a small U wave appears after the T wave. . The P wave is produced by atrial depolarization, and its amplitude represents the magnitude of the electric potential generated by atrial excitation. The QRS complex is generated by ventricular depolarization and reflects the electrical activity of ventricular depolarization. A typical QRS complex consists of three closely connected potential fluctuations: the first downward wave is the Q wave, followed by a high and sharp upward R wave, and finally a downward S wave. However, in different leads, these three waves may not all appear. The T wave represents the potential difference of uncancelled ventricular repolarization. Since the electric potential of cardiac excitation is mostly offset, the T wave appears relatively weak, and its amplitude is not lower than 1/10 of the R wave in the same lead. Abnormal T waves indicate myocardial ischemia or injury. The U wave is a low and wide wave that may appear at 0.02-0.045 after the T wave, and its direction is generally consistent with the T wave.

The most important thing in ECG signal analysis is the detection part of QRS complex wave. At present, QRS complex wave detection algorithms include wavelet algorithm, geometric matching algorithm, slope vector waveform (SVW) algorithm and so on. Although these methods have a high success rate in detecting QRS complexes, they have the disadvantage of high algorithm complexity.

Contents of the invention

In order to overcome the disadvantages of existing ECG monitoring instruments, such as high price, large size, and unsuitability for ordinary wards and patients' home monitoring, the present invention provides a low-cost portable three-lead wireless ECG monitoring system, which is easy to use, low in cost, With many advantages such as small size, it is suitable for general hospital wards and patient home monitoring applications. At the same time, in order to overcome the shortcomings of the existing ECG analysis algorithm, such as high complexity, the present invention provides an ECG analysis method. On the premise of being able to effectively identify the QRS complex wave of the ECG, the method has the characteristics of a simple algorithm and is suitable for embedded systems. application.

The present invention first designs a low-cost and low-power wireless ECG monitoring system. The system has many advantages such as simple and practical circuit, low power consumption, and low cost, and can complete real-time monitoring of patient's ECG data. This system is suitable for general hospital ward monitoring and personal family monitoring and other purposes. The present invention also proposes a kind of electrocardiogram analysis method at the same time, especially the detection algorithm of QRS complex wave, this algorithm complexity is low and detection success rate is high, has solved

According to one aspect of the present invention, a novel portable three-lead real-time wireless ECG monitoring system is provided, including an ECG acquisition electrode 1, an ECG acquisition module 2, a data processing module 3, a wireless module 4, a power supply module 5 and a console The upper computer 6, wherein, the ECG acquisition electrode 1, the ECG acquisition module 2, the data processing module 3, the wireless module 4, and the console upper computer 6 are connected in sequence, wherein: the ECG acquisition electrode 1 is used to pick up the weak The ECG signal is sent to the ECG acquisition module 2, and after processing such as amplification and filtering, the data processing module 3 performs sampling and digital signal processing, and then sends it to the wireless network via the wireless module 4 and finally sends it to the console. The power supply module 5 Responsible for converting external power supply to system power supply and reference voltage.

Preferably, there are three ECG acquisition electrodes, two of which are signal extraction electrodes, and one is a right leg driving electrode.

Preferably, the ECG acquisition module 2 includes an input buffer stage 7, a right leg drive circuit 13, and also includes a pre-instrument amplifier stage 8, a high-pass filter 9, an intermediate amplifier stage 10, a low-pass filter 11, The power frequency notch filter 12, the two signal extraction electrodes of the ECG collection electrode 1 are connected to the input end of the input buffer stage 7, and the output end of the input buffer stage 7 is connected to the pre-instrument amplifier stage 8 The input terminal of the power frequency notch filter 12 is connected to the AD input terminal of the data processing module 3, and the output terminals of the input buffer stage 7 are added and connected to the right leg drive circuit 13 The input end of the right leg drive circuit 13 is connected to the right leg drive electrode of the electrocardiographic collection electrode 1 .

Preferably, the power frequency trap 12 is a 50Hz power frequency trap.

Preferably, the power supply module 5 is responsible for converting the external power supply into 5V power supply for the ECG acquisition module 2, 1.3V and 2.5V reference voltages, and 3.3V power supply for the data processing module 3 and the wireless module 4.

Preferably, the ECG acquisition module 2 adopts a single-power low-power design, and the intermediate reference voltage of the ECG acquisition module 2 is realized in the form of a power supply voltage divider plus a voltage follower. The input buffer 7 and the right leg drive Circuit 13 adopts TI's low-power operational amplifier TL064, the pre-instrument amplifier 8 adopts ADI's micro-power amplifier AD8236, and the high-pass filter 9, intermediate amplification stage 10, and low-pass filter 11 adopt TI company's LMV324 operational amplifier.

According to another aspect of the present invention, a novel portable three-lead real-time wireless ECG monitoring and analysis method is also provided, including the steps of: using the console host computer to first perform differential processing on the received ECG data, and then perform low-pass filtering and threshold value processing, and then find the R point through R wave detection, and then find the Q and S points corresponding to this R point, and finally mark the Q, R, S points and display them on the computer screen.

In a preferred solution, the above object of the present invention is achieved in this way: the novel portable three-lead real-time wireless ECG monitoring system includes ECG acquisition electrodes, ECG acquisition module, data processing module, one-to-many wireless module, Power supply, upper computer software. Wherein: ECG acquisition and processing module includes analog signal amplification filter circuit, signal sampling, digital signal processing part. The analog signal amplification and filtering circuit includes an input buffer, a pre-amplifier, a high-pass filter, an intermediate amplification stage, a low-pass filter and a 50Hz power frequency notch filter. This part of the instrumentation amplifier and the operational amplifier are powered by a 5V single power supply, which is provided by the power module. The signal sampling and digital signal processing part is realized by ARM Cortex-M3 microcontroller with low power consumption and low cost. The power supply part converts the external input power supply into 5V and 3.3V regulated power supplies for analog circuits and digital circuits. The whole system can be powered by dry cell or lithium battery. The upper computer software includes QRS complex wave detection algorithm, ECG waveform display, ECG database and other parts.

The ECG acquisition electrode collects the ECG signal on the surface of the human skin, transmits it to the ECG acquisition module, and sequentially passes through input buffering, instrument amplification, high-pass filtering, intermediate amplification, low-pass filtering and 50Hz power frequency notch, and enters the data after AD sampling The processing module is then sent to the wireless network through the wireless module, and finally the PC of the console performs waveform display, QRS complex wave detection, database processing and other work.

The portable real-time wireless ECG detection system proposed by the present invention has three ECG acquisition electrodes, two of which are used for signal acquisition, and the other is used as a right leg drive electrode to improve the common mode rejection capability of the circuit. Electrode positions can be placed as required.

In the portable three-lead real-time wireless ECG detection system proposed by the present invention, its ECG acquisition modules are all designed with a single power supply and low power consumption, and the intermediate reference voltage is realized in the form of a power supply voltage divider plus a voltage follower, which can meet the requirements of the reference voltage. Requirements, but also achieved the purpose of low cost and low power consumption. The input buffer and the right leg drive circuit use TI's low-power operational amplifier TL064, the pre-instrumentation amplifier adopts ADI's micro-power consumption instrumentation amplifier AD8236, and the subsequent stages of amplification and filtering circuits use TI's LMV324 operational amplifier.

The data processing module of the portable real-time wireless ECG detection system proposed by the present invention is mainly realized by the STM32F103 microprocessor. The ECG acquisition module sends the amplified and filtered ECG signal to the AD interface of the microprocessor for data sampling, the microprocessor further processes the data, and finally sends it to the wireless network through the wireless module. The data processing module is completely powered by 3.3V.

In the portable real-time wireless ECG detection system proposed by the present invention, its power module is responsible for converting the external power supply into 5V and 3.3V regulated power supplies for use by analog circuits and digital circuits, and provides stable 1.3V and 2.5V reference voltages as ECG The intermediate reference voltage of the acquisition circuit.

Compared with the prior art, the beneficial effects of the present invention are: the present invention proposes a low-cost, low-power, portable real-time wireless ECG detection system, which solves the problem that the existing electrocardiograph cannot monitor in real time or the cost and power consumption Disadvantages that are too high for portable applications. The invention also proposes an electrocardiogram QRS complex wave detection algorithm, which is simple and reliable, and solves the shortcoming of the existing algorithm being too complicated. This system is suitable for general hospital ward monitoring or family personal monitoring.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Fig. 1 is a system block diagram of the present invention;

Fig. 2 is a structural block diagram of the ECG acquisition module;

Figure 3 is a flow chart of the QRS complex wave detection algorithm.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

FIG. 1 is a block diagram of the system structure of the present invention, including an electrocardiographic collection electrode 1, an electrocardiographic collection module 2, a data processing module 3, a wireless module 4, a power supply module 5, and a console host computer 6.

The ECG acquisition electrode 1 is composed of three electrodes, two of which are signal electrodes, and one is a driving electrode of the right leg. The signal electrode is responsible for picking up the body surface ECG signal, and the right leg driving electrode is responsible for feeding back the common-mode voltage of the human body to improve the common-mode rejection capability of the circuit. When in use, the signal electrodes can be placed at corresponding positions according to the measured standard ECG lead data, and the driving electrodes of the right leg can be placed at convenient positions.

The electrocardiogram acquisition electrode 1 picks up the weak electrocardiogram signal (usually a few mV) on the surface of the human body, and sends it to the electrocardiogram acquisition module 2. After processing such as amplification and filtering, the data processing module 3 performs sampling and digital signal processing, and then passes through The wireless module 4 is sent into the wireless network and finally sent to the console host computer 6. After the console host computer 6 obtains the data, it uses the QRS complex wave detection algorithm to mark Q, R, and S points and display them on the computer screen. The power supply module 5 is responsible for converting the external power supply into the power supply and reference voltage required by the circuit, wherein the 5V power supply and 1.3V and 2.5V reference voltages are used by the ECG acquisition module 2, and the 3.3V power supply is used by the data processing module 3 and the wireless module 4.

Fig. 2 shows the structural representation of the ECG acquisition module 2 of the present invention, including an input buffer stage 7, a pre-instrument amplifier stage 8, a high-pass filter 9, an intermediate amplifier stage 10, a low-pass filter 11, and a power frequency notch filter 12. Right leg driving circuit 13. Two electrocardiographic signal electrodes are connected to the input ends of the input buffer stage 7 respectively, and the output ends of the two input buffer stages 7 are respectively connected to two input ends of the pre-instrument amplifier stage 8, and the pre-instrument amplifier stage 8 The output end links to each other with the input end of high-pass filter 9, and the output end of high-pass filter 9 links to each other with the input end of intermediate amplification stage 10, and the output end of this intermediate amplification stage 10 links to each other with the input end of low-pass filter 11, and this low The output end of the pass filter 11 is connected to the input end of the power frequency notch filter 12 , and the output end of the power frequency notch filter 12 is connected to the AD interface of the data processing module 3 . In addition, in order to improve the common mode rejection effect of the circuit, the outputs of the two input buffer stages 7 are summed and connected to the input end of the right leg drive circuit 13, and the input end of the right leg drive circuit 13 is connected to the right leg drive electrode.

FIG. 3 is a flow chart of the QRS complex wave detection algorithm of the present invention. After the host computer receives the ECG data, it first performs differential processing, then performs low-pass filtering and threshold processing, and then uses the corresponding algorithm to find the R point, then finds the Q and S points corresponding to this R point, and finally marks the Q point. , R, S points and display on the computer screen.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (1)

1. A novel portable three-lead real-time wireless ECG monitoring system is characterized in that it comprises ECG acquisition electrodes (1), ECG acquisition module (2), data processing module (3), wireless module (4), Power supply module (5) and console host computer (6), wherein, ECG acquisition electrode (1), ECG acquisition module (2), data processing module (3), wireless module (4), and console host computer (6) Connect sequentially, wherein: ECG acquisition electrodes (1) are used to pick up the weak ECG signals on the human body surface, and send them to the ECG acquisition module (2). After amplification and filtering, the data processing module (3) performs Sampling and digital signal processing, and then sent to the wireless network via the wireless module (4) and finally sent to the console, the power module (5) is responsible for converting the external power supply into system power and reference voltage; There are three electrocardiographic acquisition electrodes, two of which are signal extraction electrodes, and one is a right leg drive electrode; The ECG acquisition module (2) includes an input buffer stage (7), a right leg drive circuit (13), and also includes a pre-instrument amplifier stage (8), a high-pass filter (9), an intermediate amplifier stage ( 10), low-pass filter (11), power frequency notch filter (12), two signal extraction electrodes of described ECG collection electrode (1) are connected with the input end of described input buffer stage (7), so The output end of the input buffer stage (7) is connected to the input end of the pre-instrument amplifier stage (8), and the output end of the power frequency notch filter (12) is connected to the AD of the data processing module (3). The input ends are connected, and the output ends of the input buffer stage (7) are added and connected to the input ends of the right leg drive circuit (13), and the output ends of the right leg drive circuit (13) are connected to the electrocardiogram The right leg driving electrode of the acquisition electrode (1) is connected; The power frequency trap (12) is a 50Hz power frequency trap; The power supply module (5) is responsible for converting the external power supply into 5V power supply and 1.3V, 2.5V reference voltage for use by the ECG acquisition module (2), as well as for the use of the data processing module (3) and the wireless module (4). 3.3V power supply; The electrocardiogram acquisition module (2) adopts a single-power low-power design, and the intermediate reference voltage of the electrocardiogram acquisition module (2) is realized by power supply voltage division and voltage follower. The input buffer stage (7) and The right leg drive circuit (13) adopts the low-power consumption operational amplifier TL064 of TI Company, and the described pre-instrument amplifier stage (8) adopts the micro-power consumption instrument amplifier AD8236 of ADI Company, and the high-pass filter (9), middle amplifier Stage (10), low-pass filter (11) adopt LMV324 operational amplifier of TI Company.