title: Multi-signal electromechanical cardiovascular monitoring on a modified home bathroom scale.
abstract: A commercially available bathroom scale was modified to enable unobtrusive and robust cardiovascular monitoring in the home. Handlebar electrodes were interfaced to an ultra-low power, two-electrode electrocardiogram (ECG) acquisition circuit providing consistent and clean heartbeat timing information. In addition, the footpad electrodes were used to detect lower-body electromyogram (EMG) and lower-body impedance plethysmogram (IPG) signals using two parallel circuits. The lower-body EMG signal was used as an indication of excessive motion of the subject on the scale. The lower-body IPG signal is related to blood flow through the legs, and will be investigated further in future studies. Finally, the component of bodyweight that varies with time--the ballistocardiogram (BCG) signal--was amplified from the existing strain gauges built into the scale. A preliminary validation was completed on five healthy subjects of varying sizes. The average signal-to-noise ratio (SNR) values computed over all five subjects for the ECG, IPG, and BCG signals were 17.2, 12.0, and 9.0 dB, respectively.
authors.affiliation: Department of Electrical Engineering, StanfordUniversity, Stanford, CA 94306, USA.
authors.forename: Omer T
authors.initials: OT
authors.lastname: Inan
authors.forename: Dookun
authors.initials: D
authors.lastname: Park
authors.forename: Gregory T A
authors.initials: GT
authors.lastname: Kovacs
authors.forename: Laurent
authors.initials: L
authors.lastname: Giovangrandi
mesh_terms: D001835:Body Weight; D002320:Cardiovascular Physiological Phenomena; D004576:Electromyography; D006801:Humans; D008991:Monitoring, Physiologic; D012039:Regional Blood Flow