Before revision:  The method is specially useful for estimating parameters in epidemiological compartmental models . We illustrate it in simulated and real data about COVID-19 spread in the US in order to assess qualitatively the peak of deaths by the disease .
After revision:  The method is specially useful for estimating parameters in epidemiological compartmental models in order to obtain qualitative properties of a disease evolution. We apply it to simulated and real data about COVID-19 spread in the US in order to assess qualitatively the peak of deaths by the disease .