Petter Steen - Academia.edu (original) (raw)
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Papers by Petter Steen
Http Dx Doi Org 10 1080 08839514 2012 687665, Jun 18, 2012
This article presents a methodology based on the mixture model to classify the real biomedical ti... more This article presents a methodology based on the mixture model to classify the real biomedical time series. The mixture model is shown to be an efficient probabilistic density estimation scheme aimed at approximating the posterior probability distribution of a certain class of data. The approximation is conducted by employing a weighted mixture of a finite number of Gaussian kernels whose
Meas Sci Technol, 2005
We report on an improved method for the prediction of the outcome from electric shock therapy for... more We report on an improved method for the prediction of the outcome from electric shock therapy for patients in ventricular fibrillation: the primary arrhythmia associated with sudden cardiac death. Our wavelet transform-based marker, COP (cardioversion outcome prediction), is compared to three other well-documented shock outcome predictors: median frequency (MF) of fibrillation, spectral energy (SE) and AMSA (amplitude spectrum analysis). Optimum specificities for sensitivities around 95% for the four reported methods are 63 ± 4% at 97 ± 2% (COP), 42 ± 15% at 90 ± 7% (MF), 12 ± 3% at 94 ± 5% (SE) and 56 ± 5% at 94 ± 5% (AMSA), with successful defibrillation defined as the rapid (<60 s) return of sustained (>30 s) spontaneous circulation. This marked increase in performance by COP at specificity values around 95%, required for implementation of the technique in practice, is achieved by its enhanced ability to partition pertinent information in the time-frequency plane. COP therefore provides an optimal index for the identification of patients for whom shocking would be futile and for whom an alternative therapy should be considered.
Notfall Rettungsmed, 1998
Resuscitation, Jan 4, 2000
Notfall Rettungsmed, 2005
Survey of Anesthesiology, 1989
Resuscitation, Jan 31, 2005
Although modern defibrillators are nearly always successful in terminating ventricular fibrillati... more Although modern defibrillators are nearly always successful in terminating ventricular fibrillation (VF), multiple defibrillation attempts are usually required to achieve return of spontaneous circulation (ROSC). This is potentially deleterious as cardiopulmonary resuscitation (CPR) must be discontinued during each defibrillation attempt which causes deterioration in the heart muscle and reduces the chance of ROSC from later defibrillation attempts. In this work defibrillation outcomes are predicted prior to electrical shocks using a neural network model to analyse VF time series in an attempt to avoid defibrillation attempts that do not result in ROSC. The 198 pre-shock VF ECG episodes from 83 cardiac arrest patients with defibrillation conversions to different outcomes were selected from the Oslo ambulance service database. A probabilistic neural network model was designed for training and testing with a cross validation method being used for the better generalisation performance. We achieved an accuracy of 75% in overall prediction with a sensitivity of 84% and a specificity of 65% using VF ECG time series of an order of 1 s in length. Pre-shock VF ECG time series can be classified according to the defibrillation conversion to a return of spontaneous circulation (ROSC) or No-ROSC.
Tidsskrift for Den norske legeforening
2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2001
IET 3rd International Conference MEDSIP 2006. Advances in Medical, Signal and Information Processing, 2006
Resuscitation, 2006
ABSTRACT
2009 International Conference on Advanced Information Networking and Applications Workshops, 2009
ABSTRACT
Notfall + Rettungsmedizin, 2005
Resuscitation, 1992
... Guidelines for advanced life support. Auteur(s) / Author(s). CHAMBERLAIN D. ; BOSSAERT L. ; C... more ... Guidelines for advanced life support. Auteur(s) / Author(s). CHAMBERLAIN D. ; BOSSAERT L. ; CARLI P. ; EDGREN E. ; EKSTROM L. ; HAPNES S. ; HOLMBERG S. ; KOSTER R. ; LINDNER K. ; PASQUALUCCI V. ; PERALES N. ; VON PLANTA M. ; ROBERTSON C. ; STEEN P. ; ...
Notfall & Rettungsmedizin, 1998
Http Dx Doi Org 10 1080 08839514 2012 687665, Jun 18, 2012
This article presents a methodology based on the mixture model to classify the real biomedical ti... more This article presents a methodology based on the mixture model to classify the real biomedical time series. The mixture model is shown to be an efficient probabilistic density estimation scheme aimed at approximating the posterior probability distribution of a certain class of data. The approximation is conducted by employing a weighted mixture of a finite number of Gaussian kernels whose
Meas Sci Technol, 2005
We report on an improved method for the prediction of the outcome from electric shock therapy for... more We report on an improved method for the prediction of the outcome from electric shock therapy for patients in ventricular fibrillation: the primary arrhythmia associated with sudden cardiac death. Our wavelet transform-based marker, COP (cardioversion outcome prediction), is compared to three other well-documented shock outcome predictors: median frequency (MF) of fibrillation, spectral energy (SE) and AMSA (amplitude spectrum analysis). Optimum specificities for sensitivities around 95% for the four reported methods are 63 ± 4% at 97 ± 2% (COP), 42 ± 15% at 90 ± 7% (MF), 12 ± 3% at 94 ± 5% (SE) and 56 ± 5% at 94 ± 5% (AMSA), with successful defibrillation defined as the rapid (<60 s) return of sustained (>30 s) spontaneous circulation. This marked increase in performance by COP at specificity values around 95%, required for implementation of the technique in practice, is achieved by its enhanced ability to partition pertinent information in the time-frequency plane. COP therefore provides an optimal index for the identification of patients for whom shocking would be futile and for whom an alternative therapy should be considered.
Notfall Rettungsmed, 1998
Resuscitation, Jan 4, 2000
Notfall Rettungsmed, 2005
Survey of Anesthesiology, 1989
Resuscitation, Jan 31, 2005
Although modern defibrillators are nearly always successful in terminating ventricular fibrillati... more Although modern defibrillators are nearly always successful in terminating ventricular fibrillation (VF), multiple defibrillation attempts are usually required to achieve return of spontaneous circulation (ROSC). This is potentially deleterious as cardiopulmonary resuscitation (CPR) must be discontinued during each defibrillation attempt which causes deterioration in the heart muscle and reduces the chance of ROSC from later defibrillation attempts. In this work defibrillation outcomes are predicted prior to electrical shocks using a neural network model to analyse VF time series in an attempt to avoid defibrillation attempts that do not result in ROSC. The 198 pre-shock VF ECG episodes from 83 cardiac arrest patients with defibrillation conversions to different outcomes were selected from the Oslo ambulance service database. A probabilistic neural network model was designed for training and testing with a cross validation method being used for the better generalisation performance. We achieved an accuracy of 75% in overall prediction with a sensitivity of 84% and a specificity of 65% using VF ECG time series of an order of 1 s in length. Pre-shock VF ECG time series can be classified according to the defibrillation conversion to a return of spontaneous circulation (ROSC) or No-ROSC.
Tidsskrift for Den norske legeforening
2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2001
IET 3rd International Conference MEDSIP 2006. Advances in Medical, Signal and Information Processing, 2006
Resuscitation, 2006
ABSTRACT
2009 International Conference on Advanced Information Networking and Applications Workshops, 2009
ABSTRACT
Notfall + Rettungsmedizin, 2005
Resuscitation, 1992
... Guidelines for advanced life support. Auteur(s) / Author(s). CHAMBERLAIN D. ; BOSSAERT L. ; C... more ... Guidelines for advanced life support. Auteur(s) / Author(s). CHAMBERLAIN D. ; BOSSAERT L. ; CARLI P. ; EDGREN E. ; EKSTROM L. ; HAPNES S. ; HOLMBERG S. ; KOSTER R. ; LINDNER K. ; PASQUALUCCI V. ; PERALES N. ; VON PLANTA M. ; ROBERTSON C. ; STEEN P. ; ...
Notfall & Rettungsmedizin, 1998