程控双时值放大器在检测体表窦房结电图中的应用

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

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。

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.