Title :
QT measurement for TU fused ECG morphology as exhibited during hypoglycaemia
Author :
Ireland, R.H. ; Robinson, R.T.C.E. ; Heller, S.R. ; Harris, N D
Author_Institution :
Dept. of Med. Phys. & Clinical Eng., R. Hallamshire Hosp., Sheffield, UK
fDate :
29 Oct-1 Nov 1998
Abstract :
During hypoglycaemia, there is typically a change in the ECG characterised by a flattened and prolonged T wave, often accompanied by a fused U wave. In the presence of such U waves, there is no widely accepted method of measuring the QT interval. This study compares two possible methods: using the intersection of the isoelectric line and (1) the T wave, and (2) a tangent to the T wave. The methods were tested on 306 sets of high resolution ECG data recorded during hyperinsulinaemic hypoglycaemic clamp studies. A value of measurement subjectivity was also recorded for each measurement. Results show that the tangent method is more consistent and reproducible than the non-tangent method. Further, the non-tangent method was shown to be significantly more subjective than using a tangent. The tangent method is less reliant on observer experience, is more easily defined and should be considered when ECG data sets have a large number of U waves
Keywords :
electrocardiography; gradient methods; medical signal processing; signal resolution; waveform analysis; Bland Altman plot; QT interval measurement; TU fused ECG morphology; automatic method development; flattened prolonged T wave; fused U wave; high resolution ECG; hypoglycaemia; isoelectric line intersection; measurement subjectivity; tangent method; Clamps; Clinical diagnosis; Electrocardiography; Heart rate interval; Hospitals; Morphology; Neodymium; Particle measurements; Physics; Strontium;
Conference_Titel :
Engineering in Medicine and Biology Society, 1998. Proceedings of the 20th Annual International Conference of the IEEE
Conference_Location :
Hong Kong
Print_ISBN :
0-7803-5164-9
DOI :
10.1109/IEMBS.1998.745884