Beat to beat analysis of mechanical heart valves by means of return map
- 1 January 2007
- journal article
- research article
- Published by Informa UK Limited in Journal of Medical Engineering & Technology
- Vol. 31 (2), 94-100
- https://doi.org/10.1080/03091900500221218
Abstract
Three mechanical heart valves (two bileaflet prostheses and a tilting one) were investigated in a basic hardware setup in order to evaluate with a hydrophone their opening and closing action in time and in amplitude of each beat. The recorded signal was then segmented into the series of cycles xi(t) having a temporal duration equal to the working period imposed on the valve. Two return maps were defined, in order to evaluate the degree of dispersion of the resulting scatter plot: (i) the amplitude map xi(t) versus xi+1(t); (ii) the delay map for the closure of the valve within each beat versus the successive ones. To evaluate the results obtained, two indices were proposed based on both the degree of dispersion and the deviation of the regression line of the resulting scatter plot with respect to the bisector of the map plane. The tilting disc valve showed a lower degree of dispersion, both in the amplitude signal and in the closure time delays, with respect to the other two bileaflet heart valves. The methodology proposed here could be regarded as an alternative non-invasive tool to investigate the dynamic behaviour of prosthetic heart valves, especially in the case of their suspected failure.Keywords
This publication has 12 references indexed in Scilit:
- Characterization and quantification of the return map of RR intervals by Pearson coefficient in patients with acute myocardial infarctionAutonomic Neuroscience, 2003
- Poincare mapping for detecting abnormal dynamics of cardiac repolarizationIEEE Engineering in Medicine and Biology Magazine, 2002
- Estimation of pulmonary arterial pressure by a neural network analysis using features based on time-frequency representations of the second heart soundMedical & Biological Engineering & Computing, 2002
- Correlation among Poincare´plot indexes and time and frequency domain measures of heart rate variabilityJournal of Medical Engineering & Technology, 2001
- A Three-dimensional Analysis of Flow in the Pivot Regions of an ATS Bileaflet ValveThe International Journal of Artificial Organs, 1999
- Acoustic Assessment of the Physical Integrity of Bjo¨rk-Shiley Convexo-Concave Heart ValvesCirculation, 1997
- Spectral composition of heart sounds before and after mechanical heart valve implantation using a modified forward-backward Prony's methodIEEE Transactions on Biomedical Engineering, 1996
- A three-dimensional, time-dependent analysis of flow through a bileaflet mechanical heart valve: Comparison of experimental and numerical resultsJournal of Biomechanics, 1996
- Differences in spectral composition between monostrut Bjork-Shiley and Carbomedics valves implanted in the aortic postionMedical & Biological Engineering & Computing, 1995
- Phonocardiogram signal analysis: Techniques and performance comparisonJournal of Medical Engineering & Technology, 1993