Laguerre-model blind system identification: cardiovascular dynamics estimated from multiple peripheral circulatory signals

• Published in: IEEE transactions on biomedical engineering Vol. 52; no. 11; pp. 1889 - 1901
• Main Authors: McCombie, D.B., Reisner, A.T., Asada, H.H.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.11.2005; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Animals; Arterial blood pressure; biomedical signal processing; blind system identification; Blood Circulation - physiology; Blood Flow Velocity - physiology; Blood Pressure - physiology; cardiac output; Cardiac Output - physiology; Cardiology; Computer Simulation; Deconvolution; Diagnosis, Computer-Assisted - methods; Gold; Heart - physiology; Hemodynamics; Measurement standards; Models, Cardiovascular; multiple sensor fusion; Parameter estimation; Pattern Recognition, Automated - methods; physiologic monitoring; Pressure measurement; Pulsatile Flow - physiology; Shape; Signal processing; Studies; Swine; System identification
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/TBME.2005.856260

This paper presents a method for comparing multiple circulatory waveforms measured at different locations to improve cardiovascular parameter estimation from these signals. The method identifies the distinct vascular dynamics that shape each waveform signal, and estimates the common cardiac flow input shared by them. This signal-processing algorithm uses the Laguerre function series expansion for modeling the hemodynamics of each arterial branch, and identifies unknown parameters in these models from peripheral waveforms using multichannel blind system identification. An effective technique for determining the Laguerre base pole is developed, so that the Laguerre expansion captures and quickly converges to the intrinsic arterial dynamics observed in the two circulatory signals. Furthermore, a novel deconvolution method is developed in order to stably invert the identified dynamic models for estimating the cardiac output (CO) waveform from peripheral pressure waveforms. The method is applied to experimental swine data. A mean error of less than 5% with the measured peripheral pressure waveforms has been achieved using the models and excellent agreement between the estimated CO waveforms and the gold standard measurements have been obtained.