FloHR: Ubiquitous Heart Rate Measurement Using Indirect Floor Vibration Sensing

Heart rate is one of the most critical metrics for human health. Most common methods for measuring human heart rate involve body contact, whether from wearable devices or manual measurement. However, such devices can cause discomfort to some patients. Past work for non-contact or remote heart rate measurement (e.g., camera or radio) is often limited by line-of-sight requirements that are not always possible in the real-world environment.This paper presents FloHR, 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 are propagated as vibration through the structures the person is in contact with (e.g., a chair) and through the floor. FloHR then detects and interprets these small floor vibrations. We developed a highly sensitive vibration sensing system and heartbeat pattern modelling to identify these tiny vibrations among other body motions and ambient noise.We evaluated FloHR in a real home environment, demonstrating an average heart rate error similar to medical device standards on the floor near the subjects’ chair, and on the order of 10 beats per minute (bpm) on the floor 2 meters away from the subject.