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在观察心电示波器或记录心电图时,常见的一个主要问题,是在输出波形中表现出各种干扰,影响电子诊断的结果,严重时电子诊断仪器无法工作。外界干扰主要有人体周围的高压电源与人体通过静电耦合产生的干扰;大电流电路与人体通过磁耦合产生的干扰;噪声电流流过人体产生电压降以后引起的阻抗耦合干扰,内部噪声主要有电子诊断仪器电路的各种噪声。消除干扰和噪声的主要措施是采用正确的屏蔽,如磁屏蔽、静电屏蔽、电磁屏蔽等;合理的接地;选用低噪声元器件和差动式放大器的电路形式或采用滤波装置,将噪声和干扰加以适当地滤除,不过这样,与噪声或干扰相同频带的信号成分也会受到影响,信
One of the most common problems with ECG oscilloscopes or ECG recordings is the presence of various disturbances in the output waveforms that affect the results of electronic diagnostics. In severe cases, electronic diagnostic instruments do not work. External interference is mainly caused by high voltage power supply around the human body and the human body through electrostatic coupling interference; large current circuit and the human body through magnetic coupling interference; noise current flows through the human body produces voltage drop caused by the impedance coupling interference, the internal noise is mainly electronic Diagnostic equipment circuit of various noise. The main measures to eliminate interference and noise are to use the correct shielding, such as magnetic shielding, electrostatic shielding, electromagnetic shielding, etc .; reasonable grounding; low-noise components and differential amplifier circuit or the use of filtering devices, the noise and interference To be properly filtered, however, the signal components in the same frequency band as noise or interference will be affected as well