Lifelight is a novel, calibration-free, software-only medical device that contactlessly measures pulse rate and blood pressure by measuring remote photoplethysmography (rPPG) signals of a patient's face using a standard smartphone or tablet camera.

By conducting this validation study we aimed to demonstrate the accuracy of Lifelight for classifying the full range of clinically relevant blood pressures as hypertensive or non-hypertensive and demonstrate its accuracy for measuring pulse rate and the blood pressure of people with blood pressures relevant to Stage 1 hypertension.

Lifelight was investigated in a study that followed the data collection and data analysis methodology outlined in ISO 81060-2:2018/AMD 1:2020 "Non-invasive Sphygmomanometers - Part 2: Clinical investigation of automated measurement type". This validation study was conducted by independent laboratory Element Materials Technology Boulder (formerly Clinimark), a global leader for clinical testing of vital sign data for medical devices and consumer wearable products. The study generated data from 85 people aged 18-85 with the wide-ranging distribution of blood pressures specified in ISO 81060-2:2018/AMD 1:2020.The accuracy of Lifelight's blood pressure measurements was assessed by comparing Lifelight's measurements with measurements made by dual-observer manual auscultation using the same-arm sequential method specified in ISO 81060-2:2018/AMD 1:2020. The accuracy of Lifelight's pulse rate measurements was assessed by comparing Lifelight's measurements with concurrent ECG-derived heart rate values. Data was collected in an Independent Review Board-approved study conducted by independent laboratory Clinimark (now Element) in the USA and repurposed for the testing of the new improved model in the latest version of the Lifelight® EA device. The data collected consists of 85 participants, with three readings each. The participants were resting before their measurements were taken to ensure stable blood pressure. For each Lifelight measurement, two sets of blood pressure measurements were taken using dual-observer manual auscultation. The first measurement was taken before the Lifelight measurement and the second just after. If there was too much variation between the before and after measurement, or between the two independent observers, the measurement was discarded and repeated. For this validation procedure, the measurements taken during the original study were re-processed in the new updated algorithm.

Inclusion Criteria:

• Healthy volunteers aged 18 to 85 years old

Exclusion Criteria:

• Participants were excluded from the study if they were medically unsuitable for participation at time of visit, any heart dysrhythmias (except respiratory sinus arrhythmia) as confirmed with a 3 lead ECG, compromised circulation or peripheral vascular disease, clotting disorders, female participants who were pregnant or trying to get pregnant, excessive facial hair, and conditions that affect the skin, such as anaemia, jaundice, rosacea, psoriasis, acute acne, and erythropoietic protoporphyria.

Participants could choose to withdraw themselves from the study without prejudice or they could be withdrawn by study investigators for predetermined reasons. Data excluded from the analysis was documented with justifications.