Development of a Smart Seat Cushion for Heart Rate Monitoring Using Ballistocardiography

For many individuals with cardiac conditions, long term monitoring of heart vitals is an essential part of ongoing care. Current monitoring technologies, such as wearables and medical devices, though accurate, are obtrusive, require the person to remember to use them, and need to be used correctly. Wearable monitors are, therefore, not ideal for everyone. This research developed a prototype portable seat cushion that can capture heart rate using a cardiovascular signal called the ballistocardiogram (BCG) by a person simply sitting on the cushion. The cushion uses load cells embedded inside it as well as analog and digital signal conditioning to obtain BCG, which is then processed to calculate heart rate. Results from nine participants sitting still show that the cushion is able to obtain an average accuracy of 95.1%, which is as good as or better than other similar methods reported in the literature. To the authors' knowledge, this work represents the first portable ambient device for measuring heart rate from a seated position. The smart seat cushion can easily be integrated into an Ambient Assisted Living (AAL) system and offers a zero-effort and unobtrusive alternative to wearable monitoring devices.