References of "Desaive, Thomas"
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See detailModel-based analysis of induced endotoxic shock in pigs with and without hemofiltration,
Kok, K.; Starfinger, C.; Hann, C. E. et al

in Prodeedings of the Engineering & Physical Sciences in Medicine and Australian Biomedical Engineering Conference (EPSM ABEC 2008 (2008)

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See detailSecond sound and shock waves in rigid crystals: an extended thermodynamic analysis
Lebon, Georgy ULg; Dauby, Pierre ULg; Desaive, Thomas ULg et al

in Proceedings of CHT-08 ICHMT International Symposium on Advances in Computational Heat Transfer (2008)

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See detailImproving model-based cardiac diagnosis with an ECG
Hann, C. E.; Chase, J. G.; Desaive, Thomas ULg et al

in Proceedings (CD) of the 4th European Congress for Medical and Biomedical Engineering (eMBEC 2008), Antwerp, Belgium, Nov 23-27, 2008 (2008)

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See detailModel-Based Assessment of Right Ventricular Arterial Coupling During Septic Shock – Results With a Porcine Model
Desaive, Thomas ULg; Lambermont, Bernard ULg; Janssen, N. et al

in Proceedings of the 21st European Society of Intensive Care Medicine (ESICM) Annual Congress, September 21-24, 2008, Lisbon, Portugal (2008)

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See detailModel-based cardiac diagnosis of pulmonary embolism
Starfinger, C.; Hann, C. E.; Chase, J. G. et al

in Computer Methods & Programs in Biomedicine (2007), 87(1), 46-60

A minimal cardiac model has been shown to accurately capture a wide range of cardiovascular system dynamics commonly seen in the intensive care unit (ICU). However, standard parameter identification ... [more ▼]

A minimal cardiac model has been shown to accurately capture a wide range of cardiovascular system dynamics commonly seen in the intensive care unit (ICU). However, standard parameter identification methods for this model are highly non-linear and non-convex, hindering real-time clinical application. An integral-based identification method that transforms the problem into a linear, convex problem, has been previously developed, but was only applied on continuous simulated data with random noise. This paper extends the method to handle discrete sets of clinical data, unmodelled dynamics, a significantly reduced data set theta requires only the minimum and maximum values of the pressure in the aorta, pulmonary artery and the volumes in the ventricles. The importance of integrals in the formulation for noise reduction is illustrated by demonstrating instability in the identification using simple derivative-based approaches. The cardiovascular system (CVS) model and parameter identification method are then clinically validated on porcine data for pulmonary embolism. Errors for the identified model are within 10% when re-simulated and compared to clinical data. All identified parameter trends match clinically expected changes. This work represents the first clinical validation of these models, methods and approach to cardiovascular diagnosis in critical care. (c) 2007 Elsevier Ireland Ltd. All rights reserved. [less ▲]

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See detailCardiovascular haemodynamics and ventriculo-arterial coupling in an acute pig model of coronary ischaemia-reperfusion
Lanoye, Lieve; Segers, Patrick; Tchana-Sato, Vincent ULg et al

in Experimental Physiology (2007), 92(1), 127-137

Although reperfusion after coronary occlusion is mandatory for myocardial salvage, reperfusion may trigger a cascade of harmful events (reperfusion injury) adding to myocardial injury. We investigated ... [more ▼]

Although reperfusion after coronary occlusion is mandatory for myocardial salvage, reperfusion may trigger a cascade of harmful events (reperfusion injury) adding to myocardial injury. We investigated effects of reperfusion on left ventricular (LV) haemodynamics and ventriculo-arterial (VA) coupling in pigs following acute myocardial ischaemia induced by coronary artery occlusion. Experiments were performed in six animals, with measurements of cardiac and arterial function at baseline, after 60 min of ischaemia (T60) and after 2 (T180) and 4 h of reperfusion (T300). Ventriculo-arterial coupling was assessed using the ventriculo-arterial elastance ratio of paper, as well as using a 'stiffness coupling' and 'temporal coupling' index. Reperfusion following ischaemia (T180 versus T60) induced a progressive decline in cardiovascular function, evidenced by a decrease in mean arterial blood pressure, cardiac output and ejection fraction which was not restored at T300. Although reperfusion also induced an increase in slope of the end-systolic pressure-volume relationship (ESPVR), the ESPVR curve shifted to the right, associated with a depression of contractile function. Histology demonstrated irreversible myocardial damage at T300. The ventriculo-arterial elastance ratio and the 'stiffness coupling' index were unaffected throughout the protocol, but the 'temporal coupling' parameter indicated a relative shift between heart period and the time constant of the arterial system. It is unlikely that these alterations are attributable to ischaemic injury alone. The combination of both the stiffness and temporal coupling index may provide more information when studying ventriculo-arterial coupling than the more commonly used ventricular end-systolic stiffness/effection arterial elastance (E-es/E-a) ratio. [less ▲]

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See detailStudy of ventricular interaction during pulmonary embolism using clinical identification in a minimum cardiovascular system model.
Desaive, Thomas ULg; Ghuysen, Alexandre ULg; Lambermont, Bernard ULg et al

in Proceedings of the IEEE (2007)

Cardiovascular disturbances are difficult to diagnose and treat because of the large range of possible underlying dysfunctions combined with regulatory reflex mechanisms that can result in conflicting ... [more ▼]

Cardiovascular disturbances are difficult to diagnose and treat because of the large range of possible underlying dysfunctions combined with regulatory reflex mechanisms that can result in conflicting clinical data. Thus, medical professionals often rely on experience and intuition to optimize hemodynamics in the critically ill. This paper combines an existing minimal cardiovascular system model with an extended integral based parameter identification method to track the evolution of induced pulmonary embolism in porcine data. The model accounts for ventricular interaction dynamics and is shown to predict an increase in the right ventricle expansion index and a decrease in septum volume consistent with known physiological response to pulmonary embolism. The full range of hemodynamic responses was captured with mean prediction errors of 4.1% in the pressures and 3.1% in the volumes for 6 sets of clinical data. Pulmonary resistance increased significantly with the onset of embolism in all cases, as expected, with the percentage increase ranging from 89.98% to 261.44% of the initial state. These results are an important first step towards model-based cardiac diagnosis in the Intensive Care Unit. [less ▲]

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See detailModelling the cardiovascular system
Shaw, G. M.; Chase, J. G.; Starfinger, C. et al

in Critical Care and Resuscitation : Journal of the Australasian Academy of Critical Care Medicine (2007), 9(3), 264-269

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See detailAn Extended thermodynamic approach of suspensions
Lebon, Georgy ULg; Lhuillier, D.; Dauby, Pierre ULg et al

in 3rd International Meeting of IEEES (2007)

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See detailModel-based sensor of hemodynamics in critical care
Hann, C. E.; Starfinger, C.; Chase, J. G. et al

in ICST 2007 (2007)

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See detailConfirmation of high cytokine clearance by hemofiltration with a cellulose triacetate membrane with large pores: an in vivo study
Delanaye, Pierre ULg; Lambermont, Bernard ULg; Dogné, Jean-Michel ULg et al

in International Journal of Artificial Organs (2006), 29(10), 944-948

Objective: To confirm in vivo the hypothesis that hemofiltration with a large pore membrane can achieve significant cytokine clearance. Method: We used a well-known animal model of endotoxinic shock (0.5 ... [more ▼]

Objective: To confirm in vivo the hypothesis that hemofiltration with a large pore membrane can achieve significant cytokine clearance. Method: We used a well-known animal model of endotoxinic shock (0.5 mg/kg of lipopolysaccharide from Escherichia Coli over a period of 30 mins). Six pigs were hemofiltrated for 3 hours with a large pore membrane (78 angstrom pore, 80 kDa cut off) (Sureflux FH 70, Nipro, Osaka, Japan). The ultrafiltration rate was 45 ml/kg/min. Samples were taken from arterial, venous line and in the ultrafiltrate at T120 and T240. We measured concentrations of interleukin 6, interleukin 10 and albumin. Results: At T120 and T240, the IL-6 clearances were 22 +/- 7 and 15 +/- 3 ml/min, respectively. The IL-6 sieving coefficients were 0.97 and 0.7 at T120 and T240, respectively. At T120 and T240, the IL-10 clearances were 14 +/- 4 and 10 +/- 7 ml/min, respectively. The sieving coefficients were 0.63 and 0.45 at T120 and T240, respectively. The concentrations of IL-6 and IL-10 were the same at T0 and T240. At T60 and T240, the plasmatic albumin concentrations were 24 +/- 4 g/L and 23 +/- 4 g/L, respectively ( p = 0.13). Conclusions: In this animal model of endotoxinic shock, we confirm the high cytokine clearance observed when hemofiltration is applied to a large pore membrane. The loss of albumin seems negligible. The impact of such clearances on hemodynamic stability and survival remains to be proved. [less ▲]

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See detailSteady flows of a laterally heated ferrofluid layer: Influence of inclined strong magnetic field and gravity level
Hennenberg, M.; Weyssow, B.; Slavtchev, S. et al

in Physics of Fluids (2006), 18(9),

A horizontal ferrofluid layer is submitted to a lateral heating and to a strong oblique magnetic field. The problem, combining the momentum and heat balance equations with the Maxwell equations ... [more ▼]

A horizontal ferrofluid layer is submitted to a lateral heating and to a strong oblique magnetic field. The problem, combining the momentum and heat balance equations with the Maxwell equations, introduces two Rayleigh numbers, Ra the gravitational one and Ram the magnetic one, to represent the buoyancy and the Kelvin forces, which induce motion, versus the momentum viscous diffusion and heat diffusion. Whatever the inclination of the magnetic field, the steady solution of the problem is presented as a power series of a small parameter epsilon(H) measuring the ratio of variation of the magnetization across the layer divided by the magnitude of the external imposed field. For cases of physical relevance, comparisons between analytical and numerical studies have lead to a major statement: in the strong field region (epsilon(H)<< 1) the zero order solution is the product of the Birikh solution that corresponds to the usual Newtonian fluid submitted to a lateral gradient, multiplied by a modulating factor accounting for inclination and both Rayleigh numbers. Physically, this simplified solution is valid for microgravity conditions where the magnetic field competes enough with microgravity effects to invert the laminar flow and thus suppress the motion for two specific values of the inclination angle. (c) 2006 American Institute of Physics. [less ▲]

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See detailLarge-pore membrane hemofiltration increases cytokine clearance and improves right ventricular-vascular coupling during endotoxic shock in pigs
Lambermont, Bernard ULg; Delanaye, Pierre ULg; Dogné, Jean-Michel ULg et al

in Artificial Organs (2006), 30(7), 560-564

Hemodynamic improvement in patients suffering from both septic shock and renal failure who received hemofiltration suggested that an extrarenal epuration technique could be of interest in patients with ... [more ▼]

Hemodynamic improvement in patients suffering from both septic shock and renal failure who received hemofiltration suggested that an extrarenal epuration technique could be of interest in patients with septic shock alone. However, most of the studies using continuous venovenous hemofiltration (CVVH) in this setting evidenced neither cytokine clearance nor significant reduction in their plasma level. Lack of significant clearance was explained in part by the small size of the membrane pores. Therefore, we investigated the effects of large-pore membrane hemofiltration (LPHF) during endotoxic shock in pigs on interleukin 6 (IL-6) and interleukin 10 (IL-10) clearances, and on right ventricular (RV)-vascular coupling. Thirteen anesthetized healthy pigs weighing 20-30 kg were divided into two groups. In the Endo group (n = 6), the pigs received a 0.5-mg/kg endotoxin infusion over a period of 30 mins from T0 to T30. In the EndoHF group (n = 7), LPHF (cutoff = 80 kDa) and an ultrafiltration rate of 45 mL/kg/h were started 30 mins after the end of the endotoxin infusion, from T60 to T240. In this model of porcine endotoxic shock, LPHF was responsible for a significant clearance of IL-6 (20 mL/min) and Il-10 (14 mL/min), and for an improvement in RV-vascular coupling. [less ▲]

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See detailA unified extended thermodynamic description of diffusion, thermo-diffusion, suspensions, and porous media
Lebon, Georgy ULg; Desaive, Thomas ULg; Dauby, Pierre ULg

in Journal of Applied Mechanics-Transactions of the Asme (2006), 73(1), 16-20

It is shown that extended irreversible thermodynamics (EIT) provides a Unified description of a great variety of processes, including matter diffusion, thermo-diffusion, suspensions, and fluid flows in ... [more ▼]

It is shown that extended irreversible thermodynamics (EIT) provides a Unified description of a great variety of processes, including matter diffusion, thermo-diffusion, suspensions, and fluid flows in porous media. This is achieved by enlarging the set of classical variables, as mass, momentum and temperature by the corresponding fluxes of mass, momentum and heat. For simplicity, we consider only Newtonian fluids and restrict ourselves to a linear analysis: quadratic and higher order terms in the fluxes are neglected. In the case of diffusion in a binary mixture, the extra flux variable is the diffusion flux of one the constituents, say the solute. In thermo-diffusion, one adds the heat flux to the set of variables. The main result of the present approach is that the traditional equations of Fick, Fourier Soret, and Dufour are replaced by time-evolution equations for the matter and heat fluxes, such generalizations are useful in high-frequency processes. It is also shown that the analysis can be easily extended to the study of particle suspensions in fluids and to flows in porous media, when such systems can be viewed as binary mixtures with a solid and a fluid component. [less ▲]

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See detailDynamics of spontaneous ventricular fibrillation in acutely ischemic pigs
Desaive, Thomas ULg; Janssen, Nathalie ULg; Péters, F. et al

in Europace : European Pacing, Arrhythmias, and Cardiac Electrophysiology : Journal of the Working Groups on Cardiac Pacing, Arrhythmias, and Cardiac Cellular Electrophysiology of the European Society of Cardiology (2006), 8 (supplement 1)

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