Jean-Pierre Drouhard

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A comparison between traditional numerical integration methods and a new hybrid integration method for the reconstruction of action potential activity is presented, using a mathematical model of the cardiac Purkinje fiber (MNT model). It is shown that the hybrid integration method reduces importantly the overall computation time required for solving the(More)
The purpose of this paper is to revise the parameters of the Hodgkin-Huxley formulation for the Na+ current in ventricular myocardial cells. To this end we have assembled much of the recent voltage clamp data on cardiac preparations obtained with modern voltage clamp and patch clamp techniques. The selected activation and inactivation characteristics of the(More)
Abstraet-A neural network approach is proposed to build the first stage of an Automatic Handwritten Signature Verification System. The directional Probability Density Function was used as a global shape factor and its discriminating power was enhanced by reducing its cardinality via filtering. Various experimental protocols were used to implement the(More)
Shape matrices have been used as a representation of planar shapes like industrial parts or printed characters. In this paper, we investigate the use of shape matrices as a mixed shape factor for off-line signature verification. By mixed shape factor we mean any global shape factor where the position of local measurements are take into account in the(More)
Relative changes in the sodium conductance of the resting cardiac cell membrane are often estimated from relative changes in the maximum rate of rise of the action potential (Vmax). This approach has given rise to some controversy and it has not been possible so far to test it directly on an experimental basis. We have examined here the validity of this(More)
A simulation study was performed to evaluate different recovery procedures for computing the multipole components of the cardiac electrical activity. A series of dipolar potential distributions was first generated on a realistic numerical model of the human torso. Then, different procedures based on surface integration (SI) and least-squares (LS)(More)
1. The sodium and potassium conductances of the HODGKIN-HUXLEY model are simulated by a field effect transistor with a series resistor. This arrangement leads to a simple analog model of the excitable membrane (fig. 1 and 2). 2. Normally, the model is silent (fig. 3), but it becomes automatic (fig. 4) when the decay time (de-activation) of the potassium(More)
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