References of "Desaive, Thomas"
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See detailModel-Based Assessment of Dynamic FRC (DFRC)
Desaive, Thomas ULg; Chase, J. G.; Sundaresan, A. et al

in Intensive Care Medicine (2009), 35(suppl. 1), 52

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See detailWhat makes TGC protocols “T” (tight)? An analysis of data from 2 studies
Suhaimi, F.; LeCompte, A. J.; Preiser, Jean-Charles ULg et al

in Proc 9th Annual Diabetes Technology Meeting (DTM2009) (2009)

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See detailEffective arterial elastance as an index of pulmonary vascular load.
Morimont, Philippe ULg; Lambermont, Bernard ULg; Ghuysen, Alexandre ULg et al

in American Journal of Physiology - Heart and Circulatory Physiology (2008), 294(6), 2736-42

The aim of this study was to test whether the simple ratio of right ventricular (RV) end-systolic pressure (Pes) to stroke volume (SV), known as the effective arterial elastance (Ea), provides a valid ... [more ▼]

The aim of this study was to test whether the simple ratio of right ventricular (RV) end-systolic pressure (Pes) to stroke volume (SV), known as the effective arterial elastance (Ea), provides a valid assessment of pulmonary arterial load in case of pulmonary embolism- or endotoxin-induced pulmonary hypertension. Ventricular pressure-volume (PV) data (obtained with conductance catheters) and invasive pulmonary arterial pressure and flow waveforms were simultaneously recorded in two groups of six pure Pietran pigs, submitted either to pulmonary embolism (group A) or endotoxic shock (group B). Measurements were obtained at baseline and each 30 min after injection of autologous blood clots (0.3 g/kg) in the superior vena cava in group A and after endotoxin infusion in group B. Two methods of calculation of pulmonary arterial load were compared. On one hand, Ea provided by using three-element windkessel model (WK) of the pulmonary arterial system [Ea(WK)] was referred to as standard computation. On the other hand, similar to the systemic circulation, Ea was assessed as the ratio of RV Pes to SV [Ea(PV) = Pes/SV]. In both groups, although the correlation between Ea(PV) and Ea(WK) was excellent over a broad range of altered conditions, Ea(PV) systematically overestimated Ea(WK). This offset disappeared when left atrial pressure (Pla) was incorporated into Ea [Ea * (PV) = (Pes - Pla)/SV]. Thus Ea * (PV), defined as the ratio of RV Pes minus Pla to SV, provides a convenient, useful, and simple method to assess the pulmonary arterial load and its impact on the RV function. [less ▲]

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See detailModel-based diagnosis of acute pulmonary embolism - results from a porcine model
Desaive, Thomas ULg; Ghuysen, Alexandre ULg; Kolh, Philippe ULg et al

in Intensive Care Medicine (2008), 34(suppl. 1), 78

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See detailThe impact of model-based therapeutics on glucose control in an intensive care unit
Hann, C. E.; Chase, J. G.; Desaive, Thomas ULg et al

in IFMBE Proceedings (2008), 22

This paper investigates the impact of fast parameter identification methods, which do not require any forward simulations, on model-based glucose control, using retrospective data in the Christchurch ... [more ▼]

This paper investigates the impact of fast parameter identification methods, which do not require any forward simulations, on model-based glucose control, using retrospective data in the Christchurch Hospital Intensive Care Unit. The integral-based identification method has been previously clinically validated and extensively applied in a number of biomedical applications; and is a crucial element in the presented model-based therapeutics approach. Common non-linear regression and gradient descent approaches are too computationally intense and not suitable for the glucose control applications presented. The main focus in this paper is on better characterizing and understanding the importance of the integral in the formulation and the effect it has on model-based drug therapy control. As a comparison, a potentially more natural derivative formulation which has the same computation speed advantages is investigated, and is shown to go unstable with respect to modelling error which is always present clinically. The integral method remains robust. © 2009 Springer Berlin Heidelberg. [less ▲]

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See detailThe impact of model-based therapeutics on glucose control in an intensive care unit
Chase, JG; Hann, CE; Desaive, Thomas ULg et al

in Proceedings of the 4th European Congress for Medical and Biomedical Engineering (eMBEC 2008) (2008)

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See detailModel-based identification and diagnosis of a porcine model of induced endotoxic shock with hemofiltration
Starfinger, C.; Chase, J. G.; Hann, C. E. et al

in Mathematical Biosciences (2008), 216(2), 132-139

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See detailAlteration of Right Ventricular-Pulmonary Vascular Coupling in a Porcine Model of Progressive Pressure Overloading
Ghuysen, Alexandre ULg; Lambermont, Bernard ULg; Kolh, Philippe ULg et al

in Shock (Augusta, Ga.) (2008), 29(2), 197-204

In acute pulmonary embolism, right ventricular (RV) failure may result from exceeding myocardial contractile resources with respect to the state of vascular afterload. We investigated the adaptation of RV ... [more ▼]

In acute pulmonary embolism, right ventricular (RV) failure may result from exceeding myocardial contractile resources with respect to the state of vascular afterload. We investigated the adaptation of RV performance in a porcine model of progressive pulmonary embolism. Twelve anesthetized pigs were randomly divided into two groups: gradual pulmonary arterial pressure increases by three injections of autologous blood clot (n = 6) or sham-operated controls (n = 6). Right ventricular pressure-volume (PV) loops were recorded using a conductance catheter. Right ventricular contractility was estimated by the slope of the end-systolic PV relationship (Ees). Afterload was referred to as pulmonary arterial elastance (Ea) and assessed using a four-element Windkessel model. Right ventricular-arterial coupling (Ees/Ea) and efficiency of energy transfer (from PV area to external mechanical work [stroke work]) were assessed at baseline and every 30 min for 4 h. Eaincreased progressively after embolization, from 0.26 +/- 0.04 to 2.2 +/- 0.7 mmHg mL (P < 0.05). Ees increased from 1.01 +/-0.07 to 2.35 +/- 0.27 mmHg mL (P < 0.05) after the first two injections but failed to increase any further. As a result, Ees/Ea initially decreased to values associated with optimal SW, but the last injection was responsible for Ees/Ea values less than 1, decreased stroke volume, and RV dilation. Stroke work/PV area consistently decreased with each injection from 79% +/- 3% to 39% +/- 11% (P < 0.05). In response to gradual increases in afterload, RV contractility reserve was recruited to a point of optimal coupling but submaximal efficiency. Further afterload increases led to RV-vascular uncoupling and failure. [less ▲]

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See detailDiagnosing Cardiac Dysfunction and Guiding Therapy in Critical Care
Starfinger, C.; Chase, J. G.; Hann, C. et al

in Proceedings of the NZBio 2008 Conference & Exposition, (2008)

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See detailMathematical modelling and parameter identification methods in systems
Hann, C. E.; Chase, J. G.; Shaw, G. M. et al

in Proceedings of the 7th joint Australia-New Zealand Mathematics Convention (ANZMC2008) (2008)

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See detailModel-based detection of pulmonary embolism using an extended physiologically relevant, cardiovascular model
Kok, K.; Starfinger, C.; Hann, C. E. et al

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

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See detailMaking sense of the Chaos: Model-based CVS monitoring and decision support in critical care
Shaw, G. M.; Chase, J. G.; Hann, C. E. et al

in Proceedings of the NZ Physiological Society 2008 Medical Science Congress (MedSci 2008) (2008)

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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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