In this paper, we consider a reduced parameter (RP) model for the effect of the drug atracurium on the neuromuscular blockade (NMB) level of patients undergoing general anesthesia. We propose a generalization of a previously introduced parameter estimation process to obtain the patient dependent parameters of the RP model. Furthermore, we consider a reference tracking problem, where the objective is to force the NMB level of the patients to follow a constant reference, and suggest an open-loop control law based on the estimated RP model. It turns out that the application of the identification process requires choosing two values. In this context, we present an experimental study whose goal is to clarify how these choices impact on the results of the reference tracking problem.