A computer-implemented method for quantitatively determining a persons neuro-muscular blockade (NMB) level in real-time using at least one sensor attached to the person is provided. The method includes receiving a first input signal from the sensor, wherein the first input signal includes a measurement of a first muscular response, the first muscular response resulting from a baseline stimulus current delivered to the person before administration of NMB agents to the person, and establishing a baseline chronaxie based on the first input signal. The method also includes delivering one or more stimulus currents to the person after the administration of NMB agents to the person, receiving a second input signal from the sensor, wherein the second input signal includes a measurement of one or more muscular responses resulting from the one or more stimulus currents, and determining the persons NMB level based on the second input signal.