Experimental study to redesign visual display terminal workstation for bifocal operators

摘要

Bifocal VDT (Visual Display Terminal) operators (50) were studied from different fields (data entry, conversational task, programming, CAD/CAM etc.) through user-product-environment system. Users profile includes experiments pertaining to users reactions, while products profile covers designs, manufacturing and marketing of existing computer furniture in the market. Existing VDT workstations were observed inappropriate for bifocal people facing vision problem, which was analysed thoroughly in simulated laboratory conditions by preparing a test rig with adjustable monitor angle from horizontal. Work posture of VDT operators was assessed with EMG, Photogram Metric Technique, and Centre of Gravity in four stages of test rig. An ergonomics criterion for redesigning VDT workstation was developed. It is appropriate and natural for the man-machine-environment system and also allows comfortable posture and greater efficiency of bifocal and normal VDT operators.