Non-contact, synchronous dynamic measurement of respiratory rate and heart rate based on dual sensitive regions

Abstract

BackgroundCurrently, many imaging photoplethysmography (IPPG) researches have reported non-contact measurements of physiological parameters, such as heart rate (HR), respiratory rate (RR), etc. However, it is accepted that only HR measurement has been mature for applications, and other estimations are relatively incapable for reliable applications. Thus, it is worth keeping on persistent studies. Besides, there are some issues commonly involved in these approaches need to be explored further. For example, motion artifact attenuation, an intractable problem, which is being attempted to be resolved by sophisticated video tracking and detection algorithms.MethodsThis paper proposed a blind source separation-based method that could synchronously measure RR and HR in non-contact way. A dual region of interest on facial video image was selected to yield 6-channels Red/Green/Blue signals. By applying Second-Order Blind Identification algorithm to those signals generated above, we obtained 6-channels outputs that contain blood volume pulse (BVP) and respiratory motion artifact. We defined this motion artifact as respiratory signal (RS). For the automatic selections of the RS and BVP among these outputs, we devised a kurtosis-based identification strategy, which guarantees the dynamic RR and HR monitoring available.ResultsThe experimental results indicated that, the estimation by the proposed method has an impressive performance compared with the measurement of the commercial medical sensors.ConclusionsThe proposed method achieved dynamic measurement of RR and HR, and the extension and revision of it may have the potentials for more physiological signs detection, such as heart rate variability, eye blinking, nose wrinkling, yawn, as well as other muscular movements. Thus, it might provide a promising approach for IPPG-based applications such as emotion computation and fatigue detection, etc.Electronic supplementary materialThe online version of this article (doi:10.1186/s12938-016-0300-0) contains supplementary material, which is available to authorized users.

The Importance of Respiratory Rate Monitoring: From Healthcare to Sport and Exercise

“…However, the post-processing of video images is generally time consuming when compared to the majority of contact-based techniques, and infrared video images are usually analyzed after data collection. Other contactless sensors that can simultaneously register f R , face expressions and cardiovascular variables are RGB camera sensors and depth sensors [23,189,190]. When the area of the upper chest is filmed, RGB camera sensors can be used to retrieve respiration-induced body movements from the post-processing of video images [132].…”

“…When the area of the upper chest is filmed, RGB camera sensors can be used to retrieve respiration-induced body movements from the post-processing of video images [132]. Alternatively, if the face of the user is recorded with a camera, RGB camera sensors can be used to extract f R from the modulation of the video PPG signal [189].…”

A Survey on Computer Vision for Assistive Medical Diagnosis From Faces

“…In most of these studies, the estimation of pulse is strongly correlated with the heart rate assessed from finger sensors or electrocardiograms, presenting 1-2% errors. However, while the acquisition process for monitoring the vascular pulse has been simplified, further challenges related to motion artifacts such as respiratory and head movements still require to be taken into consideration [51], [54], [.It has been recently suggested [58] that using two regions of interest could be a solution to evaluate dynamic heart rate by detecting other physiological signs (eg. eye blinking, yawning).…”

Design and Clinical Evaluation of a Non-Contact Heart Rate Variability Measuring Device

“…Due to the mentioned drawbacks within the existing measurement processes and ever increasing number of possible medical, research and commercial fields of applications, researchers worldwide are exploring the possibilities of experimental non-contact measuring techniques. Several promising novel methods are emerging with encouraging results [ 21 , 22 , 23 , 24 ].…”