References of "Dauby, Pierre"
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See detailSubject-specific cardiovascular system model-based identification and diagnosis of septic shock with a minimally invasive data set: animal experiments and proof of concept.
Chase, J Geoffrey; Lambermont, Bernard ULg; Starfinger, Christina et al

in Physiological Measurement (2011), 32(1), 65-82

A cardiovascular system (CVS) model and parameter identification method have previously been validated for identifying different cardiac and circulatory dysfunctions in simulation and using porcine models ... [more ▼]

A cardiovascular system (CVS) model and parameter identification method have previously been validated for identifying different cardiac and circulatory dysfunctions in simulation and using porcine models of pulmonary embolism, hypovolemia with PEEP titrations and induced endotoxic shock. However, these studies required both left and right heart catheters to collect the data required for subject-specific monitoring and diagnosis-a maximally invasive data set in a critical care setting although it does occur in practice. Hence, use of this model-based diagnostic would require significant additional invasive sensors for some subjects, which is unacceptable in some, if not all, cases. The main goal of this study is to prove the concept of using only measurements from one side of the heart (right) in a 'minimal' data set to identify an effective patient-specific model that can capture key clinical trends in endotoxic shock. This research extends existing methods to a reduced and minimal data set requiring only a single catheter and reducing the risk of infection and other complications-a very common, typical situation in critical care patients, particularly after cardiac surgery. The extended methods and assumptions that found it are developed and presented in a case study for the patient-specific parameter identification of pig-specific parameters in an animal model of induced endotoxic shock. This case study is used to define the impact of this minimal data set on the quality and accuracy of the model application for monitoring, detecting and diagnosing septic shock. Six anesthetized healthy pigs weighing 20-30 kg received a 0.5 mg kg(-1) endotoxin infusion over a period of 30 min from T0 to T30. For this research, only right heart measurements were obtained. Errors for the identified model are within 8% when the model is identified from data, re-simulated and then compared to the experimentally measured data, including measurements not used in the identification process for validation. Importantly, all identified parameter trends match physiologically and clinically and experimentally expected changes, indicating that no diagnostic power is lost. This work represents a further with human subjects validation for this model-based approach to cardiovascular diagnosis and therapy guidance in monitoring endotoxic disease states. The results and methods obtained can be readily extended from this case study to the other animal model results presented previously. Overall, these results provide further support for prospective, proof of concept clinical testing with humans. [less ▲]

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See detailInfluence of thermoelectric coupling on ectopic beats generated by mechano-electric feedback (MEF) in a one-dimensional cardiac fiber model
Collet, Arnaud ULg; Desaive, Thomas ULg; Pierard, Luc ULg et al

in 9th Belgian Day on Biomedical Engineering, Friday November 26th 2010 in the Academy Palace, Hertogstraat 1, 1000 Brussels (2010, November 26)

The influence of thermal processes on electrophysiology has clearly been underlined by Bini et al., using a FitzHugh--Nagumo-type (FHN-type) model. When the temperature is raised, the action potential ... [more ▼]

The influence of thermal processes on electrophysiology has clearly been underlined by Bini et al., using a FitzHugh--Nagumo-type (FHN-type) model. When the temperature is raised, the action potential duration (APD) has been shown to shorten, while the action potential (AP) amplitude decreases, and the conduction velocity increases. In this research, we investigate the effects of thermoelectric coupling on mechano-electric feedback (MEF), and more specifically, on ectopic beats generated by MEF. To investigate these effects, thermoelectric coupling is introduced in a one-dimensional electromechanical model of a cardiac fiber, which considers excitation-contraction coupling (ECC), as well as MEF. [less ▲]

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See detailModeling the instantaneous pressure-volume relationship in the left ventricle
Lucas, Alexandra ULg; Dauby, Pierre ULg; Desaive, Thomas ULg et al

in 9th Belgian Day on Biomedical Engineering, Friday November 26th 2010 in the Academy Palace, Hertogstraat 1, 1000 Brussels (2010, November 26)

Models and simulations are very useful to study interactions between anatomic structures and physical cardiac phenomena. In this work, we are interested in models of the instantaneous pressure-volume ... [more ▼]

Models and simulations are very useful to study interactions between anatomic structures and physical cardiac phenomena. In this work, we are interested in models of the instantaneous pressure-volume relationship, i.e. isochrone models. More precisely, we concentrate on the 6 models considered by Lankhaar et al. [1]. We propose a critical analysis of the work of these authors and suggest some improvement of their procedure. [1] Lankhaar J.-W. et al. Modeling the Instantaneous Pressure–Volume Relation of the Left Ventricle: A Comparison of Six Models. Annals of Biomedical Engineering, Volume 37, Number 9, 1710-1726, 2009. [less ▲]

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See detailInfluence of thermoelectric coupling on ectopic beats generated by mechano-electric feedback (MEF) in a one-dimensional cardiac fiber model
Collet, Arnaud ULg; Desaive, Thomas ULg; Pierard, Luc ULg et al

Poster (2010, November 26)

The influence of thermal processes on electrophysiology has clearly been underlined by Bini et al., using a FitzHugh--Nagumo-type (FHN-type) model. When the temperature is raised, the action potential ... [more ▼]

The influence of thermal processes on electrophysiology has clearly been underlined by Bini et al., using a FitzHugh--Nagumo-type (FHN-type) model. When the temperature is raised, the action potential duration (APD) has been shown to shorten, while the action potential (AP) amplitude decreases, and the conduction velocity increases. In this research, we investigate the effects of thermoelectric coupling on mechano-electric feedback (MEF), and more specifically, on ectopic beats generated by MEF. To investigate these effects, thermoelectric coupling is introduced in a one-dimensional electromechanical model of a cardiac fiber, which considers excitation-contraction coupling (ECC), as well as MEF. [less ▲]

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See detailminimal cardiovascular system model including physiological mitral valve opening
Paeme, Sabine ULg; Moorhead, Katherine ULg; chase, J. Geoffrey et al

in 9th Belgian National Day on Biomedical Engineering, Bruxelles, 26th november (2010, November 26)

A minimal cardiovascular system (CVS) model has been previously validated in silico, and in several animal model studies. It accounts for valve dynamics by means of a Heaviside function to simulate the ... [more ▼]

A minimal cardiovascular system (CVS) model has been previously validated in silico, and in several animal model studies. It accounts for valve dynamics by means of a Heaviside function to simulate the “open on pressure, close on flow” law. However, this model does not describe the progressive valve opening and therefore, it is not suitable for studying valve dysfunctions. [less ▲]

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See detailMinimal cardiovascular system model including physiological mitral valve opening
Paeme, Sabine ULg; Moorhead, Katherine ULg; Chase, J. Geoffrey et al

Poster (2010, November 26)

This research describes a new closed-loop cardiovascular system (CVS) model including a model of the left atrium and a model describing the progressive aperture of the mitral valve

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See detailModeling the instantaneous pressure-volume relationship in the left ventricle
Lucas, Alexandra ULg; Dauby, Pierre ULg; Kolh, Philippe ULg et al

Poster (2010, November 26)

Pressure-volume loops are a common modeling tool of the cardiovascular system. They are very useful because they characterize the global function of the cardiac pump and can also be analyzed ... [more ▼]

Pressure-volume loops are a common modeling tool of the cardiovascular system. They are very useful because they characterize the global function of the cardiac pump and can also be analyzed by considering the various phases of the cardiac cycle and marking each point of a cycle with the corresponding time. When several loops are considered, the points corresponding to the same time t in each loop can be joined to define a curve named isochrone. In this work, we are interested in models of the instantaneous pressure-volume relationship, i.e. isochrone models. More precisely, we concentrate on the 6 models considered by Lankhaar et al. [1] and we propose a critical analysis of the work of these authors and suggest some improvement of their procedure. [1] Lankhaar J.W. et al. Annals of Biomedical Engineering, Volume 37, Number 9, 1710-1726, 2009. [less ▲]

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See detailA Simplified Rotational Spring Model for Mitral Valve Dynamics
Moorhead, K. T.; Hann, C. E.; Chase, J. Geoffrey et al

in Proceedings of control 2010 (2010, September 07)

A simple non-linear rotational spring model has been implemented to model the motion of mitral valve, located between the left atrium and ventricle. A measured pressure difference curve was used as the ... [more ▼]

A simple non-linear rotational spring model has been implemented to model the motion of mitral valve, located between the left atrium and ventricle. A measured pressure difference curve was used as the input into the model, which represents an applied torque to the valve chords. Various damping and hysteresis states were investigated to find a model that best matches reported animal data of chord movement during a heartbeat. The study is limited by the use of one dataset from the literature, however results clearly highlight some physiological issues such as the damping and chord stiffness changing within one cardiac cycle. Very good correlation was achieved between modeled and experimental valve angle, indicating good promise for future simulation of cardiac dysfunction, such as mitral regurgitation or stenosis. [less ▲]

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See detailMathematical model of the mitral valve and the cardiovascular system, application for studying, monitoring and in the diagnosis of valvular pathologies
Paeme, Sabine ULg; Moorhead, Katherine ULg; Chase, J. Geoffrey et al

in UKACC international Conference on Control 2010 : Coventry, 7-10 september 2010 (2010, September 07)

A cardiovascular and circulatory system (CVS) model has been validated in silico, and in several animal model studies. It accounts for valve dynamics using Heaviside functions to simulate a physiological ... [more ▼]

A cardiovascular and circulatory system (CVS) model has been validated in silico, and in several animal model studies. It accounts for valve dynamics using Heaviside functions to simulate a physiological accurate “open on pressure, close on flow” law. Thus, it does not consider the real time scale of the valve aperture dynamics and thus doesn’t fully capture valve dysfunction particularly where the dysfunction involves partial closure. This research describes a new closed-loop CVS model including a model describing the progressive aperture of the mitral valve and valid over the full cardiac cycle. This new model is solved for a healthy and diseased mitral valve. [less ▲]

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See detailPatient-specific modelling of the cardiovascular system – application to septic shock with a minimal data set
Desaive, Thomas ULg; Chase, J. G.; Starfinger, C. et al

in World Congress on Medical Physics and Biomedical Engineering, September 7 - 12, 2009, Munich, Germany (2010)

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See detailAssessment of ventricular-arterial coupling with a model-based sensor
Desaive, Thomas ULg; LAMBERMONT, Bernard ULg; GHUYSEN, Alexandre ULg et al

in Proceedings of CONTROL 2010 (2010)

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See detailTime varying elastance estimation in an 8 camber cardiovascular system model
Desaive, Thomas ULg; Chase, J. G.; Hann, C. E. et al

in Intensive Care Medicine (2010), 36(2), 151-151

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See detailUsing time-dependent reference profiles for an instability analysis of an evaporating binary liquid layer
Machrafi, Hatim ULg; Rednikov, Alexey; Colinet, Pierre et al

Poster (2010)

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See detailUsing time-dependent reference profiles for an instability analysis of an evaporating binary liquid layer
Machrafi, Hatim ULg; Rednikov, Alexey; Colinet et al

in Proceedings of the International Conference on Multiscale Comples Fluid Flows and Interfacial Phenomena, 16 (2010)

This study treats an evaporating horizontal binary-liquid layer (aqueous solution of 10 % wt ethanol) in contact with air with an imposed transfer distance. Solutal and thermal Rayleigh-B´enard-Marangoni ... [more ▼]

This study treats an evaporating horizontal binary-liquid layer (aqueous solution of 10 % wt ethanol) in contact with air with an imposed transfer distance. Solutal and thermal Rayleigh-B´enard-Marangoni instabilities are taken into account together with the Soret effect. The critical times with corresponding liquid thicknesses are calculated, showing that a critical liquid thickness can be found under which no instability can occur. [less ▲]

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See detailBénard instabilities of a binary liquid layer evaporating into an inert gas: stability of quasi-stationary and time-dependent reference profiles
Machrafi, Hatim ULg; Rednikov, A.; Colinet, Pierre et al

in Proceedings of the 5th Conference of the International Marangoni Association “Interfacial Fluid Dynamics and Processes” (2010)

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See detailLinear stability analysis of an evaporating binary liquid layer with fully transient reference profiles
Machrafi, Hatim ULg; Rednikov, Alexey; Colinet, Pierre et al

in Bulletin of the American Physical Society, Vol. 55, n°16 (2010)

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See detailMécanique analytique (1ère partie)
Dauby, Pierre ULg

Learning material (2010)

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See detailBénard instabilities in a binary-liquid layer evaporating into an inert gas
Machrafi, Hatim ULg; Rednikov, Alexey; Colinet, Pierre et al

in Journal of Colloid & Interface Science (2010), 349

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See detailMitral valve dynamics in a closed-loop model of the cardiovascular system
Paeme, Sabine ULg; Chase, J. Geoffrey; Hann, Christopher et al

Poster (2009, December 17)

A cardiovascular and circulatory system (CVS) model has been validated in silico, and in several animal model studies. It accounts for valve dynamics by means of Heaviside function to simulate “open on ... [more ▼]

A cardiovascular and circulatory system (CVS) model has been validated in silico, and in several animal model studies. It accounts for valve dynamics by means of Heaviside function to simulate “open on pressure, close on flow” law. Thus, it does not consider the real time scale of the valve aperture and thus doesn’t fully capture valve dysfunction. This research couples the CVS model with a model describing the progressive aperture of the mitral valve. [less ▲]

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See detailMitral valve dynamics in a closed-loop model of the cardiovascular system
Paeme, Sabine ULg; Chase, J. Geoffrey; Hann, christopher et al

in Archives des Maladies du Coeur et des Vaisseaux. Pratique (2009, December), hors série 1

A cardiovascular and circulatory system (CVS) model has been validated in silico, and in several animal model studies. It accounts for valve dynamics by means of Heaviside function to simulate “open on ... [more ▼]

A cardiovascular and circulatory system (CVS) model has been validated in silico, and in several animal model studies. It accounts for valve dynamics by means of Heaviside function to simulate “open on pressure, close on flow” law. Thus, it does not consider the real time scale of the valve aperture and thus doesn’t fully capture valve dysfunction. This work describes a new coupled model of the cardiovascular system that accounts for progressive mitral valve aperture. Simulations show good correlation with physiologically expected results for healthy or diseased valves. The large number of valve model parameters indicates a need for emerging, lighter and minimal mitral valve models that are readily identifiable to achieve full benefit in real-time use. These results suggest a further use of this model to track, diagnose and control valves pathologies. [less ▲]

Detailed reference viewed: 35 (12 ULg)