Smartphone for heart sound measurement in hospital: feasibility and influencing factors

Aims Smartphones have recently been utilized to measure heart sounds in the general population, but not yet in real-world hospital settings. This study aims to assess the feasibility of smartphones for heart sound measurement across various hospital departments and to identify the factors causing suboptimal heart sound measurements. Methods and results The FonoCheck app was used to measure heart sounds from the chest of 296 hospitalized patients. Two assessors independently evaluated the quality of heart sound recordings based on the presence of the first and second heart sounds. Both environmental and patient-related factors were examined for their effects on heart sound quality. Visual assessments identified 254 (86%) good-quality heart sound recordings, with lower frequencies observed in the emergency room (67%), respiratory intensive care unit (78%), and general intensive care unit (82%). The heart sound recordings were affected by various types of noise, including respiration, conversation, motion, and interference from medical devices. However, patient demographics such as sex and body mass index were not associated with poor heart sound quality (P > 0.05), except for age which had a negative impact (P = 0.003). None of the patients' comorbidities, including atrial fibrillation, coronary artery disease, heart failure, and chronic obstructive pulmonary disease, significantly affected the heart sound measurements (P > 0.05). Conclusion It is feasible to use smartphones to measure high-quality heart sounds in hospitals. However, environmental factors and patient's age may lead to suboptimal measurements. This study supports the future medical applications of FonoCheck app in hospital settings.