This article deals with a class of continuous nonlinear control systems in the presence of sampled outputs. The dynamical models under consideration are described by ordinary differential equations with additive bounded uncertainties. The linear feedback control design proposed in this article is based on an extended version of the classical invariant ellipsoid method. The stability/robustness analysis of the resulting closed-loop system involves the celebrated 'descriptor techniques' from the extended Lyapunov methodology. Finally, the implementability of the proposed control design scheme is illustrated by a computational example. A brief discussion on the principal numerical issues is also included.