Assessing Smart Phones for Generating Life-space Indicators.

Life-space is a promising method for estimating older adults' functional status. However, traditional life-space measures are costly and time consuming because they often rely on active subject participation. This study assesses the feasibility of using the global positioning system (GPS) function of smart phones to generate life-space indicators.

Cellular telephones measure activity and lifespace in community-dwelling adults: proof of principle.

Objectives: To describe a system that uses off-the-shelf sensor and telecommunication technologies to continuously measure individual lifespace and activity levels in a novel way.

Design: Proof of concept involving three field trials of 30, 30, and 21 days.

Setting: Omaha, Nebraska, metropolitan and surrounding rural region.