Summary
In intensive care, time series of vital parameters have to be analysed online, i.e. without any time delay, since there may be serious consequences for the patient otherwise. Such time series show trends, slope changes and sudden level shifts, and they are overlaid by strong noise and many measurement artefacts. The development of update algorithms and the resulting increase in computational speed allows to apply robust regression techniques to moving time windows for online signal extraction. By simulations and applications we compare the performance of least median of squares, least trimmed squares, repeated median and deepest regression for online signal extraction.
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References
Bai, Z.D. and He, X. (1999). Asymptotic Distributions of the Maximal Depth Estimators for Regression and Multivariate Location, Ann. Stat. 27 (5), 1616–1637.
Bernholt, T. (2004). Exact Algorithms for the Repeated Median, LMS, LTS and Deepest Regression, Personal Communication.
Bernholt, T. and Fried, R. (2003). Computing the Update of the Repeated Median Regression Line in Linear Time, Inf. Process. Lett. 88 (1), 111–117.
Bernholt, T., Fried, R., Gather, U. and Wegener I. (2004). Modified Repeated Median Filters, Technical Report 46, SFB 475, University of Dortmund, Germany.
Chang, W.H., McKean, J.W., Naranjo, J.D. and Sheather, S.J. (1999). High-Breakdown Rank Regression, J. Am. Stat. Assoc. 94, No. 445, 205–219.
Croux, C., Rousseeuw, P.J. and Hössjer, O. (1994). Generalized S-Estimators, J. Am. Stat. Assoc. 89, No. 428, 1271–1281.
Davies, P.L. (1993). Aspects of Robust Linear Regression, Ann. Stat. 21 (4), 1843–1899.
Davies, P.L., Fried, R. and Gather, U. (2004). Robust Signal Extraction for On-line Monitoring Data, J. Stat. Plann. Inference 122 (1–2), 65–78.
Edelsbrunner, H. and Souvaine, D.L. (1990). Computing Least Median of Squares Regression Lines and Guided Topological Sweep, J. Am. Stat. Assoc. 85, No. 409, 115–119.
Einbeck, J. and Kauermann, G. (2003). Online Monitoring with Local Smoothing Methods and Adaptive Ridging, J. Statist. Comput. Simul. 73, 913–929.
Fried, R. (2004). Robust Filtering of Time Series with Trends, J. Nonparametric Statistics 16, 313–328.
Hössjer, O., Rousseeuw, P.J. and Ruts, I. (1995). The Repeated Median Intercept Estimator: Influence Function and Asymptotic Normality, J. Multivariate Anal. 52, 45–72.
Hössjer, O., Rousseeuw, P.J. and Croux, C. (1994). Asymptotics of the Repeated Median Slope Estimator, Ann. Stat. 22 (3), 1478–1501.
Imhoff, M., Bauer, M., Gather, U. and Fried, R. (2002). Pattern Detection in Intensive Care Monitoring Time Series with Autoregressive Models: Influence of the AR-Model Order, Biom. J. 44, 746–761.
Rousseeuw, P.J. (1983). Multivariate Estimation with High Breakdown Point, in W. Grossmann, G. Pflug, I. Vincze, W. Wertz (eds.) Proceedings of the 4th Pannonian Symposium on Mathematical Statistics and Probability, Vol. B, D. Reidel Publishing Company, Dordrecht (The Netherlands).
Rousseeuw, P.J. (1984). Least Median of Squares Regression, J. Am. Stat. Assoc. 79, No. 388, 871–880.
Rousseeuw, P.J. and Hubert, M. (1999). Regression Depth, J. Am. Stat. Assoc. 94, No. 446, 388–402.
Rousseeuw, P.J. and Leroy, A.M. (1987). Robust Regression and Outlier Detection, Wiley, New York (USA).
Rousseeuw, P.J., Van Aelst, S. and Hubert, M. (1999). Rejoinder to ‘Regression Depth’, J. Am. Stat. Assoc. 94, No. 446, 419–433.
Sheather, S.J., McKean, J.W. and Hettmansperger, T.P. (1997). Finite Sample Stability Properties of the Least Median of Squares Estimator, J. Stat. Comput. Simul. 58, 371–383.
Siegel, A.F. (1982). Robust Regression Using Repeated Medians, Biometrika 69, 242–244.
Stromberg, A.J., Hössjer, O., Hawkins, D.M. (2000). The Least Trimmed Differences Regression Estimator and Alternatives, J. Am. Stat. Assoc. 95, No. 451, 853–864.
Van Aelst, S., Rousseeuw, P.J., Hubert, M. and Struyf, A. (2002). The Deepest Regression Method, J. Multivariate Anal. 81, 138–166.
Van Kreveld, M., Mitchell, J.S.B., Rousseeuw, P.J., Sharir, M., Snoeyink, J. and Speckmann, B. (1999). Efficient Algorithms for Maximum Regression Depth, Proceedings of the 15th Annual ACM Symposium of Computational Geometry, ACM Press, New York (NJ), 31–40.
Acknowledgement
We thank an anonymous referee for several insightful suggestions, particularly, for pointing out LQD and highly robust rank regression. Financial support of the Deutsche Forschungsgemeinschaft (SFB 475: ‘Reduction of Complexity for Multivariate Data Structures’) is gratefully acknowledged.
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Gather, U., Schettlinger, K. & Fried, R. Online signal extraction by robust linear regression. Computational Statistics 21, 33–51 (2006). https://doi.org/10.1007/s00180-006-0249-8
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DOI: https://doi.org/10.1007/s00180-006-0249-8