Quantitative assessment of behavior in dementia patients by continuous physical activity monitoring

The aim of this study was to examine the quantitative relationship between physical activity and heart rate in dementia patients. Acceleration at the waist, wrist and ankle and ECGs were measured by an ambulatory monitor. At the same time as these measurements subject records were noted by a psychotherapist. Fourteen late stage dementia patients and fifteen normal elderly performed daily activity between 10 am and 4 pm. Changes in heart rate were associated with changes in acceleration in both groups, but intermittent activity changes were observed in dementia patients. The mean acceleration frequency and amplitude in the dementia group were significantly lower than those in normal elderly subjects. There was no correlation between the severity of intellectual deterioration and the degree of behavior disintegration in dementia patients. The elderly shifted smoothly between activities. The dementia patients showed sudden fluctuations of activity. The ambulatory monitor is an effective method for the quantitative assessment of dementia patients