Ergonomics Evaluation Of A Manually Operated Multi-Purpose Juice Extractor
A manually operated multipurpose juice extractor was designed and constructed for use in rural and urban areas for extraction of juice from tropical fruits. The machine was ergonomically evaluated to access the anthropological and physiological workload on end-users. A total of twenty-five (25) subjects within age groups 15 to 41 years and above were selected for this study. The subjects were physically fit for performing the operation and they were acclimatized with the experimental procedure before the commencement of the evaluation. The ergonomics evaluation included anthropological measurement (measurement of the body weight, age, height and arm length and physiological evaluation (measurement of blood pressure and heart beat rate at normal rest position and after machine operation). The oxygen consumption rate and energy expended in operating the machine was also studied. The arm length of subjects ranged from 66.3-76cm for age groups 15-20 and 36-40 respectively, average body mass ranged from 54-72kg for age groups 15-20 and 31-35 respectively while average height ranged from 145-176cm for age groups 41 and above and 31-35 respectively. Highest increase in blood pressure and heart beat rate of subjects after machine operation was obtained to be 40 mmHg for age group 21-25 and 16beats/min for age group 15-20 years respectively. The highest oxygen demand and energy expended by the subjects after machine operation was 0.4144 L/min and 6.5444kJ/min respectively. Percent juice yield, extraction efficiency and extraction loss was obtained to be 65 (for age group 21-25), 41 (for age group 15-20) and 23 (for age group 31-35). Moreover, 28% subjects felt pains at the arm while 20% felt pain at the chest after operating the machine and 52% did not feel any pain after operating the machine. The machine is cost-effective, simple to operate and maintain and causes less discomfort to the users, it is therefore recommended for small local fruit processors and rural dwellers.
IndexTerms- Juice Extractor, Anthropometrics, Physiological, Performance Evaluation, Ergonomics Evaluation.