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We compared blood pressure (BP) values obtained with a new optical smartphone application (OptiBP™) with BP values obtained using a non-invasive automatic oscillometric brachial cuff (reference method) during the first 2 h of surveillance in a post-anesthesia care unit in patients after non-cardiac surgery. Three simultaneous BP measurements of both methods were recorded every 30 min over a 2-h period. The agreement between measurements was investigated using Bland-Altman and error grid analyses. We also evaluated the performance of the OptiBP™ using ISO81060-2:2018 standards which requires the mean of the differences ± standard deviation (SD) between both methods to be less than 5 mmHg ± 8 mmHg. Of 120 patients enrolled, 101 patients were included in the statistical analysis. The Bland-Altman analysis demonstrated a mean of the differences ± SD between the test and reference methods of + 1 mmHg ± 7 mmHg for mean arterial pressure (MAP), + 2 mmHg ± 11 mmHg for systolic arterial pressure (SAP), and + 1 mmHg ± 8 mmHg for diastolic arterial pressure (DAP). Error grid analysis showed that the proportions of measurement pairs in risk zones A to E were 90.3% (no risk), 9.7% (low risk), 0% (moderate risk), 0% (significant risk), 0% (dangerous risk) for MAP and 89.9%, 9.1%, 1%, 0%, 0% for SAP. We observed a good agreement between BP values obtained by the OptiBP™ system and BP values obtained with the reference method. The OptiBP™ system fulfilled the AAMI validation requirements for MAP and DAP and error grid analysis indicated that the vast majority of measurement pairs (≥ 99%) were in risk zones A and B.Trial Registration ClinicalTrials.gov Identifier: NCT04262323.

To provide information about the clinical relevance of blood pressure (BP) measurement differences between a new smartphone application (OptiBP™) and the reference method (automated oscillometric technique) using a noninvasive brachial cuff in patients admitted to the emergency department. We simultaneously recorded three BP measurements using both the reference method and the novel OptiBP™ (test method), except when the inter-arm difference was > 10 mmHg BP. Each OptiBP™ measurement required 1-min and the subsequent reference method values were compared to the values obtained with OptiBP™ using a Bland–Altman analysis and error grid analysis. Among the 110 patients recruited, OptiBP™ BP values could be collected on 61 patients (55%) and were included in the statistical analysis. The mean of differences (95% limits of agreement) between the reference method and the test method were − 0.1(− 22.5 to 22.4 mmHg) for systolic arterial pressure (SAP), − 0.1(− 12.9 to 12.7 mmHg) for diastolic arterial pressure (DAP) and − 0.3(− 18.1 to 17.4 mmHg) for mean arterial pressure (MAP). The proportions of measurements in risk zones A-E were 86.9%, 13.1%, 0%, 0%, and 0% for MAP and 89.3%, 10.7%, 0%, 0%, and 0% for SAP. In this pilot study conducted in stable and awake patients admitted to the emergency department, the absolute agreement between the OptiBP™ and the reference method was moderate. However, when BP measurements were made immediately after an initial calibration, error grid analysis showed that 100% of measurement differences between the OptiBP™ and reference method were categorized as no- or low-risk treatment decisions for all patients. Trial Registration: ClinicalTrials.gov Identifier: NCT04121624.

To provide information about the clinical relevance of blood pressure (BP) measurement differences between a new smartphone application (OptiBP™) and the reference method (automated oscillometric technique) using a noninvasive brachial cuff in patients admitted to the emergency department. We simultaneously recorded three BP measurements using both the reference method and the novel OptiBP™ (test method), except when the inter-arm difference was 10 mmHg BP. Each OptiBP™ measurement required 1-min and the subsequent reference method values were compared to the values obtained with OptiBP™ using a Bland-Altman analysis and error grid analysis. Among the 110 patients recruited, OptiBP™ BP values could be collected on 61 patients (55%) and were included in the statistical analysis. The mean of differences (95% limits of agreement) between the reference method and the test method were - 0.1(- 22.5 to 22.4 mmHg) for systolic arterial pressure (SAP), - 0.1(- 12.9 to 12.7 mmHg) for diastolic arterial pressure (DAP) and - 0.3(- 18.1 to 17.4 mmHg) for mean arterial pressure (MAP). The proportions of measurements in risk zones A-E were 86.9%, 13.1%, 0%, 0%, and 0% for MAP and 89.3%, 10.7%, 0%, 0%, and 0% for SAP. In this pilot study conducted in stable and awake patients admitted to the emergency department, the absolute agreement between the OptiBP™ and the reference method was moderate. However, when BP measurements were made immediately after an initial calibration, error grid analysis showed that 100% of measurement differences between the OptiBP™ and reference method were categorized as no- or low-risk treatment decisions for all patients.Trial Registration: ClinicalTrials.gov Identifier: NCT04121624.