Evaluation of a Novel Optical Smartphone Blood Pressure Application: A Method Comparison Study against Invasive Arterial Blood Pressure Monitoring in Intensive Care Unit Patients

Abstract BackgroundArterial hypertension is a public health problem worldwide. It is currently diagnosed and monitored non-invasively using the oscillometric method. Being able to measure blood pressure (BP) using a smartphone application could provide more widespread access to hypertension screening and monitoring. In this observational study in intensive care unit patients, we compared blood pressure values obtained using a new optical smartphone application (OptiBP™; test method) with arterial BP values obtained using a radial artery catheter (reference method).MethodsWe simultaneously measured three BP values every hour for five consecutive hours on two consecutive days using the two methods. Bland-Altman and error grid analyses were used for agreement analysis between both methods. The performance of the smarphone application was investigated using the Association for the Advancement of Medical Instrumentation (AAMI) and the International Organization for Standardization (ISO) definitions, which require the bias ± SD between two technologies to be below 5 ± 8 mmHg.ResultsAmong the 30 recruited patients, 22 patients had adequate OptiBP™ values and were thus analyzed. The Bland-Altman analysis revealed a mean of the differences ± SD between both methods of 0.9 ± 7 mmHg for mean arterial pressure (MAP), 0.2 ± 14 mmHg for systolic arterial pressure (SAP), and 1.1 ± 6 mmHg for diastolic arterial pressure (DAP). Error grid analysis demonstrated that the proportions of measurement pairs in risk zones A to E were 88.8% (no risk), 10% (low risk), 1% (moderate risk), 0% (significant risk), and 0% (dangerous risk) for MAP and 88.4%, 8.6%, 3%, 0%, 0%, respectively, for SAP.ConclusionsThis method comparison study revealed good agreement between BP values obtained using the OptiBP™ and those done invasively. The OptiBP™ fulfills the AAMI/ISO universal standards for MAP and DAP (but not SAP). Error grid showed that the most measurements (≥ 97%) were in risk zones A and B.ClinicalTrials.gov registrationNCT04728477