Poster presented at the 2006 European Respiratory Society meeting, Munich, de.

Assessment of physical activity using a multisensor armband

Thierry Troosters, PT PhD, Daniel Langer, PT Msc, Didier Saey, PT PhD , Rik Gosselink PT PhD, Marc Decramer MD PhD

Abstract

Physical activity in daily life is becoming an increasingly important patient centered outcome in chronic diseases, including COPD. Monitoring of activity levels, however, is technically difficult due to the low movement intensity. We have used the dynaport activity monitor as the gold standard to measure activities in daily life. The device has the advantage of a lower limb sensor which makes it relatively accurate in detecting slow movement. More recently the Armband (AB; Sensewear Pro, Body media, US) became available. This tool uses two accelerometers two temperature sensors (skin and ‘near body’) and galvanic skin response to estimate energy expenditure through reprogrammed algorithms (Innerview Professional 5.0) . It is worn at the upper right triceps and allows for 14 days of recording. We compared the Physical activity level estimate from the DAM and the as well as the number of steps registered by both devices. 24 subjects (5 healthy, 6 stable COPD, and 13 Lung transplant candidates did wear both devices simultaneously for at least two days, yielding 92 days of comparison of both devices. Pre transplant patients were with both devices significantly less active (PALDAM 1.14±0.2; PALAB 1.18±0.23) compared to stable COPD (PALDAM 1.38±0.24; PALAB 1.47±0.26) and healthy subjects (PALDAM 1.33±0.21; PALAB 1.72±0.47). There was a significant relation between PALDAM and PALAB (R=0.73, p<0.001).The number of steps counted per day was underestimated with the AB (3172±3350 day-1) compared to the DAM (3409±2907 day-1 p=0.002). We conclude that the agreement between both tools for general activity level is acceptable, the armband, underestimates steps, in slowly walking subjects. Physical activity level however, has a good agreement between both devices.

Publication: Poster presented at the 2006 European Respiratory Society meeting, Munich, Germany.