Authors:
Walter Karlen
1
;
Guy Dumont
1
;
Chris Petersen
2
;
Jennifer Gow
2
and
J. Mark Ansermino
2
Affiliations:
1
The University of British Columbia, Canada
;
2
BC Children’s Hospital, Canada
Keyword(s):
Pulse detection, Heart rate estimation, Mobile phones, Embedded systems, Photoplethysmography, Vocoder.
Related
Ontology
Subjects/Areas/Topics:
Biomedical Engineering
;
Biomedical Instruments and Devices
;
Devices
;
Embedded Signal Processing
;
Health Monitoring Devices
;
Human-Computer Interaction
;
Physiological Computing Systems
Abstract:
Mobile phones can be used as a platform for clinical decision making in resource-poor and remote areas. Their limited battery and computational resources, however, demand efficient and low-power algorithms. We present a new algorithm for the fast and economical estimation of heart rate (HR) from the photoplethysmogram (PPG) recorded with a pulse oximeter connected to a mobile phone. The new method estimates the HR frequency by adaptively modeling the PPG wave with a sine function using a modified phase vocoder. The obtained wave is also used as an envelope for the detection of peaks in the PPG signal. HR is either computed using the vocoder center frequency or the peak intervals in a histogram. Experiments on a mobile device show comparable speed performance with other time domain algorithms. Preliminary tests show that the HR computed from the vocoder center frequency is robust to Noise in the PPG. The instantaneous HR calculated with the vocoder peak detection method was more sensi
tive to short-term HR variations than the vocoder center frequency method. These results point to further developments using a combination of both HR estimation methods that will enable the robust implementation of adaptive phase vocoders into mobile phone applications.
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