Physiological state model for human ergonomic workload.
Twenty ergonomic tasks were evaluated in which human operators performed mixed static work and dynamic work. Steady-state physiological data are the input into a model as regressor variables, which are then multiplied by the respective regressor coefficients. The resultant physiological state model output is a single response variable that represents the workload. Mixed stepping regression techniques were utilized to calculate the regressor coefficients. Ten physiological state model equations resulted. A lower order equation (with three regressor variables) accounted for 80% of the observed variance. The highest order equation (with ten regressor variables) accounted for 89% of the variance.