title: Spatial probabilistic pulsatility model for enhancing photoplethysmographic imaging systems.
abstract: Photoplethysmographic imaging (PPGI) is a widefield noncontact biophotonic technology able to remotely monitor cardiovascular function over anatomical areas. Although spatial context can provide insight into physiologically relevant sampling locations, existing PPGI systems rely on coarse spatial averaging with no anatomical priors for assessing arterial pulsatility. Here, we developed a continuous probabilistic pulsatility model for importance-weighted blood pulse waveform extraction. Using a data-driven approach, the model was constructed using a 23 participant sample with a large demographic variability (11/12 female/male, age 11 to 60 years, BMI 16.4 to 35.1??kg·m?2). Using time-synchronized ground-truth blood pulse waveforms, spatial correlation priors were computed and projected into a coaligned importance-weighted Cartesian space. A modified Parzen–Rosenblatt kernel density estimation method was used to compute the continuous resolution-agnostic probabilistic pulsatility model. The model identified locations that consistently exhibited pulsatility across the sample. Blood pulse waveform signals extracted with the model exhibited significantly stronger temporal correlation (W=35,p<0.01) and spectral SNR (W=31,p<0.01) compared to uniform spatial averaging. Heart rate estimation was in strong agreement with true heart rate [r2=0.9619, error (?,?)=(0.52,1.69) bpm].
authors.affiliation: University of Waterloo, Department of Systems Design Engineering, 200 University Avenue West, Waterloo N2L 3G1, CanadabSchlegel-University of Waterloo Research Institute for Aging, 250 Laurelwood Drive, Waterloo N2J 0E2, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Amelard
authors.affiliation: University of Waterloo, Department of Systems Design Engineering, 200 University Avenue West, Waterloo N2L 3G1, Canada.
authors.forename: David A
authors.initials: DA
authors.lastname: Clausi
authors.affiliation: University of Waterloo, Department of Systems Design Engineering, 200 University Avenue West, Waterloo N2L 3G1, CanadabSchlegel-University of Waterloo Research Institute for Aging, 250 Laurelwood Drive, Waterloo N2J 0E2, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Wong
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002648:Child; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D061848:Optical Imaging / Q000379:methods*; D017156:Photoplethysmography / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D055815:Young Adult