Heart rate is one of the most commonly used metrics for human health. Measuring human heart rate typically involves direct body contact, whether from wearable devices or manual measurement. However, such devices can cause discomfort in some patients, particularly in sensitive populations where such monitoring is more critical. Other past work for noncontact or remote heart rate measurement (e.g., camera- or radio-based methods) is often limited by line-of-sight and privacy requirements, which inhibit application in real-world environments. This article presents FloorPulse, an indirect heart rate monitoring system for human beings using heartbeat-induced floor vibrations. The key insight is that the human body generates a small wave of pressure and sound with each heartbeat. These waves are propagated as vibration through the structures the person is in contact with (e.g., a chair), then into and through the floor. FloorPulse detects and interprets these small floor vibrations to monitor the person’s heart rate. We developed a highly sensitive vibration sensing system and heartbeat pattern modeling to identify these tiny vibrations among other body motions and ambient noise. We evaluated FloorPulse in a real home environment, demonstrating an average heart rate error similar to medical device standards on the floor near the participants’ chair, and on the order of 10 beats per minute (bpm) on the floor 2 m away from the subject.
