Intelligent Systems For Assessing Aging Changes: home-based, unobtrusive, and continuous assessment of aging

Abstract

Objectives: To describe a longitudinal community cohort study, Intelligent Systems for Assessing Aging Changes, that has deployed an unobtrusive home-based assessment platform in many seniors homes in the existing community.

Methods: Several types of sensors have been installed in the homes of 265 elderly persons for an average of 33 months. Metrics assessed by the sensors include total daily activity, time out of home, and walking speed. Participants were given a computer as well as training, and computer usage was monitored. Participants are assessed annually with health and function questionnaires, physical examinations, and neuropsychological testing.

Results: Mean age was 83.3 years, mean years of education was 15.5, and 73% of cohort were women. During a 4-week snapshot, participants left their home twice a day on average for a total of 208 min per day. Mean in-home walking speed was 61.0 cm/s. Participants spent 43% of days on the computer averaging 76 min per day.

Discussion: These results demonstrate for the first time the feasibility of engaging seniors in a large-scale deployment of in-home activity assessment technology and the successful collection of these activity metrics. We plan to use this platform to determine if continuous unobtrusive monitoring may detect incident cognitive decline.

Figure 1.

Examples of two home layouts with coverage of sensors indicated. Red boxes (S): locations of passive infrared motion detectors; green rectangles (D): contact sensors on exit/entry doors and refrigerator doors; blue boxes (W): sensor lines for measuring walking speed; HC: home computer location. See text for details of how sensor locations were chosen.

Figure 2.

Spiral plot showing activity in two homes over 180 days of monitoring. Each day’s activity forms one concentric circle in the plot, with the timing of sensor firings indicated by the 24-hr clock (midnight at the top and noon at the bottom). The solid blue concentric circles represent 30-day markers. The colors indicate where the sensor fired: red = bathroom, green = bedroom, blue = living room, black = front door. (A) This participant lives in a Continuing Care Retirement Community and takes meals in the common dining room, falls asleep at about the same time every night, and gets up most nights at the same time to use the bathroom. (B) This participant lives alone in the community, has more irregular sleep patterns, and leaves her home much less often.