Abstract
This study describes a contactless vital sign monitoring (CVSM) system capable of measuring heart rate (HR) and respiration rate (RR) using a low-power, indirect time-of-flight (ToF) camera. The system takes advantage of both the active infrared illumination as well as the additional depth information from the ToF camera to compensate for the motion-induced artifacts during the HR measurements. The depth information captures how the user is moving with respect to the camera and, therefore, can be used to differentiate where the intensity change in the raw signal is from the underlying heartbeat or motion. Moreover, from the depth information, the system can acquire respiration rate by directly measuring the motion of the chest wall during breathing. We also conducted a pilot human study using this system with 29 participants of different demographics such as age, gender, and skin color. Our study shows that with depth-based motion compensation, the success rate (system measurement within 10% of reference) of HR measurements increases to 75%, as compared to 35% when motion compensation is not used. The mean HR deviation from the reference also drops from 21 BPM to −6.25 BPM when we apply the depth-based motion compensation. In terms of the RR measurement, our system shows a mean deviation of 1.7 BPM from the reference measurement. The pilot human study shows the system performance is independent of skin color but weakly dependent on gender and age.
Highlights
Introduction published maps and institutional affilWe demonstrate a contactless vital sign monitoring (CVSM) system based on a nearinfrared indirect time-of-flight (ToF) camera that can measure the heart rate (HR) and the respiratory rate (RR) of an individual at a stand-off distance
The second row corresponds to the raw intensity information and the bottom row corresponds to the depth information from the same regions of interest (ROI)-1
We demonstrate a contactless HR/respiration rate (RR) monitoring system based on an indirect ToF camera
Summary
Introduction published maps and institutional affilWe demonstrate a contactless vital sign monitoring (CVSM) system based on a nearinfrared indirect time-of-flight (ToF) camera that can measure the heart rate (HR) and the respiratory rate (RR) of an individual at a stand-off distance. Most contactless HR/RR measurement systems rely on photoplethysmography (PPG) using RGB (red-green-blue) cameras with visible light illumination [1,2,3,4,5,6,7,8]. Several approaches, such as the skin-tone or blind-source separation-based algorithm, are proposed for the removal of external artifacts and considerably improve the reliability of HR measurement [9,10,11,12,13,14,15,16]. In some application scenarios such as vehicle driver monitoring or patient monitoring in hospitals, RGB camerabased systems face challenges from fluctuating or very low background illumination [17]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
