title: Automatic detection of motion artifacts in the ballistocardiogram measured on a modified bathroom scale.
abstract: Ballistocardiography (BCG) is a non-invasive technique used to measure the ejection force of blood into the aorta which can be used to estimate cardiac output and contractility change. In this work, a noise sensor was embedded in a BCG measurement system to detect excessive motion from standing subjects. For nine healthy subjects, the cross-correlation of the motion signal to the BCG noise--estimated using a simultaneously acquired electrocardiogram and statistics of the BCG signal--was found to be 0.94 and 0.87, during periods of standing still and with induced motion artifacts, respectively. In a separate study, where 35 recordings were taken from seven subjects, a threshold-based algorithm was used to flag motion-corrupted segments of the BCG signal using only the auxiliary motion sensor. Removing these flagged segments enhanced the BCG signal-to-noise ratio (SNR) by an average of 14 dB (P < 0.001). This integrated motion-sensing technique addresses a gap in methods available to identify and remove noise in standing BCG recordings due to movement, in a practical manner that does not require user intervention or obtrusive sensing.
authors.affiliation: Department of Bioengineering, Stanford University, Stanford, CA, USA. rwiard@stanford.edu
authors.forename: Richard M
authors.initials: RM
authors.lastname: Wiard
authors.forename: Omer T
authors.initials: OT
authors.lastname: Inan
authors.forename: Brian
authors.initials: B
authors.lastname: Argyres
authors.forename: Mozziyar
authors.initials: M
authors.lastname: Etemadi
authors.forename: Gregory T A
authors.initials: GT
authors.lastname: Kovacs
authors.forename: Laurent
authors.initials: L
authors.lastname: Giovangrandi
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D001450:Ballistocardiography / Q000379:methods*; D002302:Cardiac Output / Q000502:physiology; D005260:Female; D006333:Heart Failure / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D055815:Young Adult