Outdoor multimodal system based on smartphone for health monitoring and incident detection

Abstract

An effective continuous monitoring system on human activities and vital signs provides a rapid detection and assistance in times of critical events. Most of today’s existing systems concentrate only on providing indoor monitoring solutions, not taking into consideration that danger is more prominent outdoors. This work proposes a multimodal system solution to monitor elderly people outdoor. The proposed solution simultaneously monitors different modalities, and detect if any problem occurs. Using state-of-the-art transmission technology, the proposed solution makes use of a heart-rate monitor to detect heart problem issues, as well as the smartphone's three-axis accelerometer and GPS to detect if a person falls and if so, to identify a person’s location, accordingly. These monitoring services are combined together in order to obtain more pertinent information about a person’s condition, and to make use of assistance services, when needed. The proposed solution was evaluated through simulation, and experiments involving 20 subjects. From the 180 tests conducted involving three different fall scenarios, results show that falls can be detected from walking or standing with 97.77% precision, 95% sensitivity, and 99.16% specificity. Moreover, the proposed solution minimizes false positive and false negative. The results obtained also validate the detection of tachycardia, the fusion of the different monitoring services, and the pertinence of assistance services with 100% success. An application was developed, and its evaluation enabled us to validate the system’s interaction with the elderly.