Portable Accelerometer Device for Measuring Human Energy Expenditure

We have developed and tested a portable device that measures energy expenditure per unit time of a human subject. A modified ceramic phonocartridge senses the acceleration of the body. After amplification and rectification a Curtis 120 CP3 elapsed time meter integrates the output. This may prove to be useful in providing an objective measurement of the level of physical activity of human subjects and can be used in studying habitual and leisure time activities in a large population setting. It is worn on the waist, weighs 400 g, measures 14 X 8 X 4 cm, costs 30 plus 5 h assembly time, and runs 10 days on two 9 V transistor batteries.