Fractional Factorial Analysis and Empirical Modeling of Cardiopulmonary Responses During Lifting Operations

Abstract

The National Institute for Occupational Safety and Health (NIOSH) developed a lifting equation in 1981 (Revised in 1991) to indicate ‘‘safe’’ occupational lifting limits. The equation uses a series of lifting multipliers (parameters) to calculate corresponding recommended task weight limits. In the present work, the interactions effect of lifting parameters has been studied by using a parameterization approach to measure the effect of interaction between factors. The main effects of load weight, frequency of lift, vertical distance of lift, horizontal distance from lift and operator and their interactions during lifting operations have been evaluated on oxygen uptake and heart rate of workers involved in continuous lifting tasks by using factorial analysis of variance and empirical modeling. As the physiological characteristics and body metabolism of Indian male workers is different as compared to other countries. Moreover due to different environmental conditions in India the work stresses involved in lifting tasks are very demanding. This factor approach has been used to study the effects of various factors at appropriate levels and their interactions among variables. Plots of significant factors, S/N ratio and empirical modeling have been used to determine the best-fit relationship between the response and the model parameters.