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Sensors 2016, 16(9), 1494;

Fast and Robust Real-Time Estimation of Respiratory Rate from Photoplethysmography

Department of Biomedical Engineering, Hanyang University, Seoul 04763, Korea
Author to whom correspondence should be addressed.
Academic Editor: Stefano Mariani
Received: 23 May 2016 / Revised: 8 September 2016 / Accepted: 9 September 2016 / Published: 14 September 2016
(This article belongs to the Section Physical Sensors)
Full-Text   |   PDF [2137 KB, uploaded 14 September 2016]   |  


Respiratory rate (RR) is a useful vital sign that can not only provide auxiliary information on physiological changes within the human body, but also indicate early symptoms of various diseases. Recently, methods for the estimation of RR from photoplethysmography (PPG) have attracted increased interest, because PPG can be readily recorded using wearable sensors such as smart watches and smart bands. In the present study, we propose a new method for the fast and robust real-time estimation of RR using an adaptive infinite impulse response (IIR) notch filter, which has not yet been applied to the PPG-based estimation of RR. In our offline simulation study, the performance of the proposed method was compared to that of recently developed RR estimation methods called an adaptive lattice-type RR estimator and a Smart Fusion. The results of the simulation study show that the proposed method could not only estimate RR more quickly and more accurately than the conventional methods, but also is most suitable for online RR monitoring systems, as it does not use any overlapping moving windows that require increased computational costs. In order to demonstrate the practical applicability of the proposed method, an online RR estimation system was implemented. View Full-Text
Keywords: respiratory rate; photoplethysmography; adaptive IIR notch filter respiratory rate; photoplethysmography; adaptive IIR notch filter

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Kim, H.; Kim, J.-Y.; Im, C.-H. Fast and Robust Real-Time Estimation of Respiratory Rate from Photoplethysmography. Sensors 2016, 16, 1494.

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