Method and device for carrying out ECG (Electrocardiograph) lead-off detection

Abstract

The invention discloses a method and a device for carrying out ECG lead-off detection. A lead-off threshold range is first set; any signal in each ECG lead channel is acquired one by one, and the acquired signals are switched and outputted every 50mS to 200mS; peak detection is carried out on the outputted signals, and if the signals are direct-current signals, the signals are directly outputted after peak detection; if the signals are power frequency interference signals containing direct-current components, the peak values of the signals are detected; and if the peak values exceed the lead-off threshold range, ECG leads come off, or else, the ECG leads do not come off. Since the invention adopts the method of peak detection to carry out ECG lead-off detection, the invention solves the problem that the software filtering in the conventional lead-off detection method can cause lead-off misjudgement when the operating environment of the equipment is poor. In a word, the invention has the advantages of low cost, high reliability, low requirements on device parameters and the like, and brings more convenience to application.

Description

technical field [0001] The present invention relates to the field of ECG signal collection and processing, in particular to the field of ECG lead-off detection and prompting, and more specifically to a method for correctly realizing ECG lead-off detection and a device for realizing the method. Background technique [0002] The existing ECG lead-off detection technology is mainly based on the DC bias method, see figure 1 , The monitoring equipment introduces the human ECG signal to the board through the electrodes, and the hardware front end of the board is equipped with a low-pass filter to filter out high-frequency interference. A buffer is set after the low-pass filter to buffer and output the front-end ECG signal. Point A or B of the input stage is buffered at the front end of the ECG, and a DC bias voltage is added through a resistor with a large resistance value. The bias voltage can be positive or negative. When the ECG electrodes are not off, due to the The closed-l...

AI Technical Summary

Problems solved by technology

In order to realize the multi-electrode lead-off judgment in the existing technical solutions, multiple channels are usually used to buffer the previous stage signal at the same time, and the lead-off signal is sent to the multi-channel AD, and the multi-channel AD completes the sampling, which will cause hardware It is more complicated and requires MCU to have multi-channel AD

[0003] The main disadvantages of the existing lead-off judgment: 1. The disadvantage of the traditional ECG lead-off detection technology is that when the system working environment is poor, the whole system is easily affected by power frequency interference. Frequency interference can easily lead to strong power frequency interference signal or even saturation in the output of the ECG front-end buffer. After the excessive power frequency interference signal passes through the software low-pass filter, it outputs an abnormal voltage value, which leads to misjudgment by the ECG lead-off circuit, and the system abnormal

2. Use the MCU to sample the output of the lead off, and use the software to judge whether the lead is off. Since the MCU has to deal with the power frequency interference in the lead off signal, the required MCU sampling rate is relatively high, and it is necessary to correctly sample the power frequency interference signal And processing, the MCU sampling rate is required to be at least 250Hz, and the MCU needs to sample and process a large amount of data in a short time, which consumes too much MCU resources

Especially when multi-channel lead-off signals are sampled and processed at the same time, the resource consumption of the MCU is greater

3. Existing technical solutions usually require multiple channels to be buffered at the same time. Each buffer channel requires an operational amplifier and a filter circuit composed of peripheral resistors and capacitors. The hardware circuit is relatively complicated.

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