Non-invasive monitoring of vital signs using recliner chair and respiratory pattern analysis
In-home monitoring has the potential to help track health changes for older adults with chronic health conditions, thereby making early treatment possible when exacerbations arise. A recliner chair is often used by older adults, even for sleeping at night, for those with breathing difficulty, neck and back problems, or other pain. Here, we present a sensor system for recliner chairs that can be used to monitor heart rate and respiration rate. The system uses two accelerometers placed strategically to capture these vital signs noninvasively and without direct contact with the body, while at same time being hidden from view. The system was tested with 45 subjects, with an average age of 78.8 years for both upright and reclined configurations of the chair. We also tested the system on 6 different types of recliner models. An accuracy of 99% for heart rate and 93% for respiratory rate was obtained. An analysis of the error distribution patterns according to age, gender and recliner configurations are considered. A validation study of a commercially available sensor, Murata SCA11H, which is primarily designed for use on the bed is tested on the chair and the results are presented in this thesis. We have also developed a measure known as the “Breathing Pattern Index” that can be useful in determining the respiratory health of the occupants on the chair. Initial studies of the effectiveness of this index and algorithm are evaluated and the results are presented. This new system and index have the potential to help in identifying very early health changes and improve health outcomes for older adults.