A Least Mean-Square Filter for the Estimation of the Cardiopulmonary Resuscitation Artifact Based on the Frequency of the Compressions

• Published in: IEEE transactions on biomedical engineering Vol. 56; no. 4; pp. 1052 - 1062
• Main Authors: Irusta $^$, Unai, Ruiz, JesÚs, de Gauna, SofÍa Ruiz, EftestØl, Trygve, Kramer-Johansen, Jo
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.04.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive filters; Algorithms; Automated external defibrillator (AED); Cardiac arrest; Cardiology; Cardiopulmonary resuscitation; cardiopulmonary resuscitation (CPR); Cardiopulmonary Resuscitation - methods; CPR; Defibrillation; Defibrillators; Electrocardiography; Frequency estimation; Heart Arrest - diagnosis; Heart Arrest - etiology; Heart Arrest - rehabilitation; Humans; least mean-square (LMS) algorithm; Least squares approximation; Models, Cardiovascular; Rhythm; Sensitivity and Specificity; Signal Processing, Computer-Assisted; sudden cardiac arrest (SCA); Testing; Ventilation; ventricular fibrillation (VF); Ventricular Fibrillation - complications; Ventricular Fibrillation - diagnosis
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/TBME.2008.2010329

Cardiopulmonary resuscitation (CPR) artifacts caused by chest compressions and ventilations interfere with the rhythm diagnosis of automated external defibrillators (AED). CPR must be interrupted for a reliable diagnosis. However, pauses in chest compressions compromise the defibrillation success rate and reduce perfusion of vital organs. The removal of the CPR artifacts would enable compressions to continue during AED rhythm analysis, thereby increasing the likelihood of resuscitation success. We have estimated the CPR artifact using only the frequency of the compressions as additional information to model it. Our model of the artifact is adaptively estimated using a least mean-square (LMS) filter. It was tested on 89 shockable and 292 nonshockable ECG samples from real out-of-hospital sudden cardiac arrest episodes. We evaluated the results using the shock advice algorithm of a commercial AED. The sensitivity and specificity were above 95% and 85%, respectively, for a wide range of working conditions of the LMS filter. Our results show that the CPR artifact can be accurately modeled using only the frequency of the compressions. These can be easily registered after small changes in the hardware of the CPR compression pads.