Noise cancellation signal processing method and computer system for improved real-time electrocardiogram artifact correction during MRI data acquisition.
Fiche publication
Date publication
avril 2007
Journal
IEEE transactions on bio-medical engineering
Auteurs
Membres identifiés du Cancéropôle Est :
Pr FELBLINGER Jacques, Dr VUISSOZ Pierre-André
Tous les auteurs :
Odille F, Pasquier C, Abächerli R, Vuissoz PA, Zientara GP, Felblinger J
Lien Pubmed
Résumé
A system was developed for real-time electrocardiogram (ECG) analysis and artifact correction during magnetic resonance (MR) scanning, to improve patient monitoring and triggering of MR data acquisitions. Based on the assumption that artifact production by magnetic field gradient switching represents a linear time invariant process, a noise cancellation (NC) method is applied to ECG artifact linear prediction. This linear prediction is performed using a digital finite impulse response (FIR) matrix, that is computed employing ECG and gradient waveforms recorded during a training scan. The FIR filters are used during further scanning to predict artifacts by convolution of the gradient waveforms. Subtracting the artifacts from the raw ECG signal produces the correction with minimal delay. Validation of the system was performed both off-line, using prerecorded signals, and under actual examination conditions. The method is implemented using a specially designed Signal Analyzer and Event Controller (SAEC) computer and electronics. Real-time operation was demonstrated at 1 kHz with a delay of only 1 ms introduced by the processing. The system opens the possibility of automatic monitoring algorithms for electrophysiological signals in the MR environment.
Mots clés
Algorithms, Artifacts, Diagnosis, Computer-Assisted, methods, Electrocardiography, methods, Humans, Image Enhancement, methods, Magnetic Resonance Imaging, methods, Reproducibility of Results, Sensitivity and Specificity, Signal Processing, Computer-Assisted
Référence
IEEE Trans Biomed Eng. 2007 Apr;54(4):630-40