提出一种简单的QRS复合波起止点的检测方法，以每个采样点及其前后分别隔一个采样点构成一个三角形，计算该采样点对应的三角形夹角和到底边的垂直高度，将满足一定条件的夹角和高度的对应点确定为Q;R或S峰，在QRS复合波前后的一定窗口内，依据夹角的大小检测QRS波群的起止点. 用24组网上提供的多通道ECG信号进行实验，结果表明：该方法能准确检测QRS复合波的起止点，在此基础上去除基线漂移，能有效地保持ST段的形态特征.

 An algorithm is proposed to detect onset and offset of QRS complex. Given a sequence of ECG signal samples, a triangle is formed by the current sample together with the sample before the previous one, and that after the following one. The interior angle corresponding to the vertex (the current sample), and the distance from the current sample to the opposite side of the triangle are calculated. If both the interior angle and the distance satisfy the pre-determined values, the current sample is judged as a Q, R or S peak. The onset and offset of QRS complex are thus found among the samples preceding and following QRS complex according to their interior angles. A total of 24 multichannel ECG records obtained from the Internet are used to test the proposed method. The experimental results show that the proposed method can accurately detect onset and offset of QRS complex, and the morphological feature of ST segment is effectively kept after its baseline wander is extracted from the ECG signal with the method.