Non-contact Home Health Monitoring Based on Low-Cost High-Performance Accelerometers

Many current home health monitoring systems are based on wearable sensors, which may compromise patient compliance and adherence due to the irritation or inconvenience of wearing, maintaining and charging such devices. In addition, most existing systems can only acquire limited relevant data and thus fall short of clinical value. In an effort to address these limitations, this paper reports the initial study of non-contact home health monitoring based on custom-designed low-cost ultrasensitive accelerometers. These sensors were developed based on a unique cascaded asymmetric-gapped cantilever structure and achieved a resolution orders of magnitude better than the ones used in smart phones and other wearable devices. Using these new sensors, we successfully demonstrated noncontact recording of ballistocardiogram (BCG), caused by the momentum of blood flow during cardiac cycle, mainly from beds, but also from the floor, chairs and sofas. Heart rate, respiration, and other physiological information can be extracted from the BCG data. We also demonstrated 3-dimensional (3-D) BCG measurement capability by mounting 3 sensors to the bed in orthogonal directions. 3D BCG not only offers richer vital signs potentially, but also enables identification of postures and thus more accurate tracking of BCG variation. This research may lead to a new home health monitoring system, which is not only unobtrusive, attendance-free, low-cost, but also offers rich physiological information.