Wearable cameras in health: the state of the art and future possibilities.

The relationships between lifestyle behaviors and health outcomes usually are based on self-reported data. Such data are prone to measurement error. In response, there has been a movement towards objective forms of measurement that have low participant and researcher burden. The papers in this theme issue in the American Journal of Preventive Medicine assess the utility of a new form of objective measurement in health research, namely wearable cameras. These devices can be worn all day and automatically record images from a first-person point of view, requiring no intervention or attention from the subject or the researcher. The most mature visual lifelogging device is Microsoft's SenseCam, a wearable camera worn via a lanyard around the neck. The SenseCam has been increasingly used in health-related research for several years. These theme papers report current research into wearable cameras in health, as presented at the SenseCam 2012 Symposium. Wearable cameras and their associated software analysis tools have developed to the point that they now appear well suited to measure sedentary behaviour, active travel, and nutrition-related behaviours. Individuals may recall events more accurately after reviewing images from their wearable cameras. Aspects of their immediate cognitive functioning may also improve. Despite the benefits of wearable cameras, there are still challenges remaining before their use becomes widespread. Ethical and privacy concerns are important issues that need to be addressed, as well as easy access to devices. In response, an ethical framework and smartphone-based wearable camera capture platform are proposed. In sum, this body of work suggests that the use of wearable cameras will soon be appropriate to understand lifestyle behaviours and the context in which the occur.