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D Chapelle

Publications and source records attributed to D Chapelle.

3 recordsLinked to original sources

Cardiac function estimation from MRI using a heart model and data assimilation: advances and difficulties.

In this paper, we present a framework to estimate local ventricular myocardium contractility using clinical MRI, a heart model and data assimilation. First, we build a generic anatomical model of the ventricles including muscle fibre orientations and anatomical subdivisions. Then, this model is deformed to fit a clinical MRI, using a semi-automatic fuzzy segmentation, an affine registration method and a local deformable biomechanical model. An electromechanical model of the heart is then presented and simulated. Finally, a data assimilation procedure is described, and applied to this model. Data assimilation makes it possible to estimate local contractility from given displacements. Presented results on fitting to patient-specific anatomy and assimilation with simulated data are very promising. Current work on model calibration and estimation of patient parameters opens up possibilities to apply this framework in a clinical environment.

Adult↗

[Study of the threshold dose of penicillin which induces an epileptogenic focus during ontogenesis in the rabbit].

A local application on the cortex surface of a very small drop of Ringer solution containing Penicillin was performed to establish the threshold dose required to elicit and epileptogenic focus and consequently the occuring latency of it. Threshold doses are small (20 - 60 International Units) and show a significant decrease during the maturation of the C.N.S. On the other hand latencies, whatever the animal's age, decrease fairly. The results are confronted to the various supposed modes of action of penicillin, modes which involve a dysfonctioning of the Na+ and K+ ionic pump.

Age Factors↗

[Effect of anoxia on the evoked somesthesic response during rabbit maturation].

The resistance to anoxy of the somesthetic evoked response (S.E.R.) has been studied on the young rabbit from birth to ten days. An obvious decrease of this resistance is being observed from the eighth day. The authors drew a parallel from their results and the well known modifications of the oxydative metabolism of the C.N.S. during maturation.

Age Factors↗