Measurement of Vital Signs Using Lifelight® Remote Photoplethysmography: results of the VISION-D and VISION-V observational studies (Preprint)

BACKGROUND Detection of early changes in vital signs (VS) enables timely intervention; however, measurement of VS requires hands-on technical expertise and is often time-consuming. Contactless measurement of VS is beneficial to prevent infection, such as during the COVID-19 pandemic. Lifelight® is a novel software being developed to measure VS by remote photoplethysmography, based on video capture of the face via the integral camera on mobile phones and tablets. We report the observational VISION-D data collection study for algorithm development (NCT04763746) and VISION-V (NCT03998098), a laboratory-based validation study of Lifelight. OBJECTIVE Data collection for algorithm development (VISION D) and software validation (VISION V) METHODS Blood pressure (BP), pulse rate (PR), and respiratory rate (RR) were measured simultaneously using Lifelight, a sphygmomanometer (BP, PR) and manual counting of RR. Accuracy performance targets for each VS were defined from a systematic literature review of the performance of state-of-the-art VS technologies. RESULTS The VISION-D dataset (17,233 measurements from 8585 participants) met the accuracy targets for RR (0.3 ± 3.6 [mean error ± SD] vs target of 2.3 ± 5.0; n=7462), PR (0.3 ± 4.0 vs 2.2 ± 9.2; n=10,214), and diastolic BP (−0.4 ± 8.5 vs 5.5 ± 8.9; n=8951); for systolic BP, mean error target was met but not SD (3.5 ± 16.8 vs 6.7 ± 15.3; n=9233). Fitzpatrick skin type did not affect accuracy. The VISION-V dataset (679 measurements from 127 participants) met all the standards: −0.1 ± 3.4 for RR; 1.4 ± 3.8 for PR; 2.8 ± 14.5 for systolic BP; −0.3 ± 7.0 for diastolic BP. CONCLUSIONS Lifelight demonstrates sufficient accuracy in the measurement of VS, particularly RR and PR, which are important early indicators of clinical deterioration. As use of Lifelight does not require specific training or equipment, the software is potentially useful for the contactless measurement of VS by non-clinical staff in residential and home care settings. INTERNATIONAL REGISTERED REPORT RR2-10.2196/14326