Sahambi J S, Tandon S N, Bhatt R K
Electrical Engineering Department, Indian Institute of Technology, Delhi, India.
Med Biol Eng Comput. 1997 Nov;35(6):747-51. doi: 10.1007/BF02510988.
Timing characterisation of the ECG using wavelet transforms is a new technique in which multiscale analysis reduces the influence of noise. This technique issued to investigate the effect of noise and to estimate the errors involved in the detection of onsets and offsets of ECG waves. With appropriate choice of scales of analysis, the study shows that the errors involved in the measurement of QRS width in the presence of base-line wander are negligible. The 50 Hz power-line interference introduces a maximum error of 6.25% if it is greater than 50% of the signal amplitude. The P and T complexes are not affected by power-line interference, but the base-line wander introduces a maximum error of 9.6%. In situations with the simultaneous presence of both types of noise, the use of an optimised scale restricts the errors to within clinically acceptable limits.
使用小波变换对心电图进行定时特征分析是一种新技术，其中多尺度分析可减少噪声的影响。该技术用于研究噪声的影响，并估计心电图波起始和结束检测中涉及的误差。通过适当选择分析尺度，研究表明，在存在基线漂移的情况下，测量QRS波宽度所涉及的误差可以忽略不计。如果50Hz电源线干扰大于信号幅度的50%，则会引入最大6.25%的误差。P波和T波群不受电源线干扰的影响，但基线漂移会引入最大9.6%的误差。在同时存在两种类型噪声的情况下，使用优化尺度可将误差限制在临床可接受的范围内。
