Observability of system state variables as a means to evaluate monitoring techniques

The authors studied whether observability of system state variables could be used to evaluate new clinical monitoring techniques or equipment by testing this approach on a peripheral nerve stimulator (PNS), which is used to control neuromuscular blockade. By applying the Kalman observability criterion to a linearized mathematical model of the pharmacokinetics and pharmacodynamics of a neuromuscular blocker (NMB), the authors demonstrated observable and unobservable ranges of one of the state variables: concentration of NMB in the peripheral compartment. Observability of this clinically relevant state variable was significantly enhanced by the PNS