程控双时值放大器在检测体表窦房结电图中的应用

采用程控双时值放大器检测体表窦房结电图,根据T波的形态与大小,选用单时值或双时值,消除高大T波通过放大器的耦合电容器所引起的伪差,使P前波清晰,起始点明确。通过200例体表窦房结电图的分析,提出使用单时值和双时值的条件和方法。

Application of Programme Double Time Constant Amplifier in Detecting Body Surface Sinus Node Electrogram

The body surface sinus node electrogram (SiNEb) v.ras recorded by using programme double time constant amplifier. The amplifier has two time constants: recordingtime constant(0,3s) and additional-time constant(<0.3s). The use of sole recording-time constant is single time constant whereas that of both constants is named double time constant. Either of the two was selected, i.e., when amplitude of T wave was small, a low frequency and low amplitude potential prior to A wave could be shown on the SNE_b with single time constant. This is known as sinus node potential (SNP) or pre-P wave. While the amplitud of T wave was large, double time constant was selected. At the moment additional time onstant was induced at the T wave-decay. Thus the artefact owing to the discharge of coupling capacitor charged by T wave was eleminated so that the SNP could be clearly shown. On the basis of analysis of 200 normal subjects' SNE_b the method of using single and double time constant is presented.