RESUMO
OBJECTIVE: A new smartphone app called Anura can measure blood pressure (BP) any time and any place without cuffs or special equipment from video of the face. This study assessed its accuracy in close conformity with the American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 standard for BP measurement devices. METHODS: We validated Anura in reference to auscultation using a mercury sphygmomanometer and then assessed accuracy against the two accuracy criteria described in the guideline (n = 85 subjects; three measurement pairs per subject). RESULTS: The mean difference between the Anura measurement and its paired auscultatory reference measurement across all 255 measurement pairs was -0.4 ± 6.7 mmHg for systolic blood pressure (SBP) and 1.2 ± 7.0 mmHg for diastolic blood pressure (DBP). Both are within the acceptable limit of 5 ± 8 mmHg and thus satisfy accuracy criterion 1. When mean differences are averaged for each subject, the mean across all 85 subjects is -0.4 ± 5.8 mmHg for SBP and 1.2 ± 6.7 mmHg for DBP. Both are within acceptable limits (based on the mean difference) and thus satisfy accuracy criterion 2. CONCLUSIONS: Anura meets ANSI/AAMI/ISO 81060-2:2013 standard with respect to BP measurement accuracy. As the ANSI/AAMI/ISO 81060-2:2013 standard has not been developed for cuffless devices, further research assessing additional accuracy issues specific to such devices is needed.
