Improving safety and operational efficiency in residential care settings with WiFi-based localization

To assess the effectiveness of a wireless network (WiFi-based) localization system (devices mounted on resident wheelchairs) in decreasing caretaker time spent searching for residents and providing alerts of residents going outdoors in a skilled nursing facility.

A controlled study over two 2-month periods approved by the institutional review board.

A long-term skilled nursing facility in Massachusetts specializing in multiple sclerosis previously instrumented with wireless network infrastructure.

Nineteen residents and 9 staff members at the facility for the first 2-month period; 9 residents and 3 staff members at the facility for the second 2-month period.

Software was installed on 4 staff computers to display the locations of residents enrolled in the study. This software was made available to enrolled staff for the second half of the first 2-month period and the entirety of the second 2-month study. In the second 2-month study, the software was modified to provide alerts if any 1 of 9 participating "high-risk"' residents went outdoors, and the accuracy of the alert system was evaluated.

In the first 2-month study, 9 staff members recorded the amount of time it took them to locate participating residents (as and when needed during the course of their daily activities). In the second 2-month study, 3 staff members recorded whether outdoor-alerts correctly identified a resident leaving the building or if it was a false alarm.

In both phases, participating staff members made frequent use of the system (44 searches and 215 outdoor alerts). Overall, the localization information decreased the average time needed to find residents by about two-thirds (from 311.1 seconds to 110.9 seconds). For outdoor alerts, the system had a false-alarm rate of 9.1% (under normal facility operations); systematic tests of the outdoor-alert system carried out by the authors had a false-negative, or missed-alarm, rate of 1.7%.

Using timely resident location information can provide significant gains for both operational efficiency (finding residents) and enhanced resident safety (outdoor alerts). This approach may provide an inexpensive alternative for facilities that have sufficient wireless infrastructure; future work should assess its effectiveness in additional settings.