Validity of a posture and movement registration device (IDEEA) under controlled conditions

Activity profiles are among the predictors of weight-loss maintenance in the DiOGenes project. These were measured using the Intelligent Device for Energy Expenditure & Activity movement registration device (IDEEA, MiniSun, CA). This study assessed the IDEEA system's ability to recognize a range of postures and activities. Seven females and four males (mean age 38y, BMI 24.2kg·m-2) wore an IDEEA monitor while resident in a whole body calorimeter for 24-hours. Twice they adopted a series of 14 lying, sitting, standing, stepping and walking activities, supervised by a researcher, for five-minutes each. Activity codes assigned by the IDEEA system were compared to the postures and activities of the subjects, and the number of incorrect, and correct and similar (e.g. correct posture but incorrect orientation) matches totalled. On average, the IDEEA system identified the controlled postures and activities correctly or similarly 70% of the time; for each these were, lying 63%, sitting 83%, standing 72%, stepping 80% and walking 52%. However, accuracy of recognition varied between subjects (range 45% to 95%), although it was