表面肌电图（sEMG）广泛应用于临床医学、康复医学、体育健身等方面的研究中，而对其进行分析的前提条件是要准确判断肌电的动作起止时刻。当 sEMG 测量位置靠近心脏时，起止点检测容易受心电（ECG）干扰而出现误判。针对影响起止点判断的 ECG 干扰的特点，本文建立了一种基于短时能量和短时过零率的肌电起止时刻判断算法，设置双阈值来自动检测 sEMG 信号端点。本算法的依据是 sEMG 与 ECG 在短时过零率上的差异，以及 sEMG 与背景噪声在短时能量上的差异。对腹直肌的 sEMG 信号采集的实验结果表明，这一算法基本不受 ECG 干扰的影响，检测结果的准确率达到 95.6%。
Surface electromyography (sEMG) has been widely used in the study of clinical medicine, rehabilitation medicine, sports, etc., and its endpoints should be detected accurately before analyzing. However, endpoint detection is vulnerable to electrocardiogram (ECG) interference when the sEMG recorders are placed near the heart. In this paper, an endpoint-detection algorithm which is insensitive to ECG interference is proposed. In the algorithm, endpoints of sEMG are detected based on the short-time energy and short-time zero-crossing rates of sEMG. The thresholds of short-time energy and short-time zero-crossing rate are set according to the statistical difference of short-time zero-crossing rate between sEMG and ECG, and the statistical difference of short-time energy between sEMG and the background noise. Experiments results on the sEMG of rectus abdominis muscle demonstrate that the algorithm detects the endpoints of the sEMG with a high accuracy rate of 95.6%.