Estimation of respiration rate using an accelerometer and thermal camera in eGlasses

Respiration rate is a very important vital sign. Different methods of respiration rate measurement or estimation have been developed. However, especially interesting are those that enable remote and unobtrusive monitoring. In this study, we investigated the use of smart glasses for the estimation of respiration rate especially useful for indoors applications. Two methods were analyzed. The first one is based on measurements of respiration-related body movements using an accelerometer. The second one uses the thermal camera to observe temperature changes in the nostril region. For both methods signals were extracted, filtered and processed using two different respiration rate estimators. Both methods were validated during experiments with the participation of volunteers using the respiration belt as a reference measurement method. Results proved that for both methods it is possible to reliable estimate the respiration rate with Root Mean Square Error lower than 2 breaths per minute, which is sufficient for medical screening.