从体表记录连续心动周期的希—浦电位

HIS-PURKINJE POTENTIAL RECORDING FROM BODY SURFACE ON CARDIAC CYCLE BASIS

HPS电位从体表记录时是十分微弱的,它往往被放大器的本机噪声,肌电噪声和50Hz市电及其高次谐波所干扰,在我们的研究中采用了一些新技术克服上述的干扰。用多路性能相同的放大器进行空间相关的方法获得性能良好的低噪声放大器,用改进LMS算法的自适应滤波器抑制50Hz市电及其高次谐波而保证HpS中相应频率成份不丢失,并且能进行实时处理;空间相关电极的使用,有效地抑制了肌电噪声,并使HPS电位得到增强。成功地在每个心跳周期内记录到了HPS电位。

<ABSTRACT> Since His-Purkinje potentials recorded from body surface is very weak and often masked by noises from muscle, instruments and 50Hz power supply, some new techniques are used in this study. To improve ratio of signal to noise, multi--channel amplifier of spatial averaging was devised by the authors. To avoid interference of noises from 50Hz power supply and its harmonics and keep His-Purkinje signal, an improved LMS adaptive filter is used in our system, the latter being capable of processing signal in real time. The technique of spatial averaging using a system of e1ectr- odes is devised so as to avoid interference of noise from muscles. On the basis of these improvements, His-Purkinje potential can be recorded from body surface on cardiac cycle (beat by beat ) basis without time averaging and shielding.