Feasibility and acceptability of smartphone technology for patients to self-record vital signs in the emergency department (The FacED Study): A study protocol

Overcrowding and high nursing workload in urgent and emergency care (UEC) settings frequently lead to incomplete or omitted measurement of patient vital signs during initial assessment and monitoring, with potential negative consequences for patient outcomes. Contactless camera‑based photoplethysmography (PPG) software, which allows patients to record a 30‑second smartphone video to obtain their own vital signs, may help reduce nursing workload, support prioritisation of clinical tasks, and decrease waiting times for triage. This study will evaluate the feasibility and acceptability of this technology in situ across three UEC services at St George's University Hospitals NHS Foundation Trust. A total of 1,500 patients will undergo both manual and smartphone‑based vital‑sign measurement, and feasibility will be assessed using a post‑measurement survey. Acceptability among triage staff will be evaluated using a short survey of 20-40 clinicians, and broader patient acceptability of digital health technologies in UEC settings will be explored through a questionnaire administered to 10,000 patients. Informed consent will be obtained before participation in any study procedures. Findings will be disseminated through peer‑reviewed publications and conference presentations and will inform future research on digital vital‑sign monitoring in UEC environments.