Copyright © 2019 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Original article 1 1359-5237 Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/MBP.0000000000000421 Accuracy testing of a new optical device for noninvasive estimation of systolic and diastolic blood pressure compared to intra-arterial measurements Cyril Pellaton a , Anna Vybornova b , Sibylle Fallet b , Luisa Marques a , Olivier Grossenbacher b , Bastien De Marco b , Valentin Chapuis b , Mattia Bertschi b , Bruce S. Alpert c, * and Josep Solà b Objective The objective of this study was to compare the systolic (S) and diastolic (D) blood pressure (BP) estimations from a new optical device at the wrist with invasive measurements performed on patients scheduled for radial arterial catheterization in the ICU. Optical signals were automatically processed by a library of algorithms from Aktiia SA (OBPM – optical blood pressure monitoring algorithms). Methods A total of 31 participants from both sexes, aged 32–87 years, were enrolled in the study (NCT03837769). The measurement protocol consisted of the simultaneous recording of reflective photoplethysmographic signals (PPG) from the cuffless optical device and the reference BP values recorded by a contralateral radial arterial catheter. From the 31 participants, 23 subjects whose reference data quality requirements were adequate were retained for further analysis. The PPG signals from these patients were then automatically processed by the Aktiia OBPM library of algorithms, which generated uncalibrated estimates of SBP and DBP. After the automatic assessment of optical signal quality, 326 pairs of uncalibrated SBP and DBP determinations from 16 patients were available for analysis. These values were finally transformed into calibrated estimations (in mmHg) using arterial catheter SBP and DBP values, respectively. Results For SBP, a mean difference (±SD) of 0.0 ± 7.1 mmHg between the arterial catheter and the optical device values was found, with 95% limits of agreement in the Bland-Altman method of –11.9 to + 12.2 mmHg (correlation of r = 0.87, P < 0.001). For DBP, a mean difference (±SD) of 0.0 ± 2.9 mmHg between arterial catheter and the optical device values was found, with 95% limits of agreement in the Bland-Altman method of –4.8 to + 5.5 mmHg (correlation of r = 0.98, P < 0.001). Conclusion SBP and DBP values obtained by radial artery catheterization and those obtained from optical measurements at the wrist were compared. The new optical technique appears to be capable of replacing more traditional methods of BP estimation. Blood Press Monit XXX:000–000 Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.Blood Pressure Monitoring 2019, XXX:000–000 Keywords: blood pressure, cuffless blood pressure, optical blood pressure monitoring algorithms, optical technology a Hopital Neuchâtelois de Pourtalès, b Aktiia SA, Neuchâtel, Switzerland and c University of Tennessee, Memphis, Tennessee, USA Correspondence to Josep Solà, PhD, Aktiia SA, Neuchâtel, Switzerland Tel: +41 32 552 20 52; e-mail: josep@aktiia.com * Retired Received 5 August 2019 Accepted 20 October 2019 Introduction The diagnosis and management of hypertension requires today the measurement of blood pressure (BP) by means of a cuff placed around the arm, generating patient dis- comfort and limiting patient compliance. Aktiia SA, a Swiss/US-based company, is currently developing a cuff- less sphygmomanometer based on a patented technology (OBPM – optical blood pressure monitoring) that uses a simple optical sensor at the wrist [1,2]. This innovative technology captures BP changes from each heartbeat without performing any arterial occlusion, hence address- ing the shortcomings of the routinely used cuffs. The aim of the present study (NCT03837769) was to compare the systolic (S) and diastolic (D) BP estimations from the Aktiia OBPM technology applied at the wrist with intra-arterial measurements in an ICU. Participants and methods Recruitment Study participants were recruited from inpatients of the HNE hospital (Hôpital Neuchâtelois) ICU. After exclu- sion of patients with atrial fbrillation and tachycardia (resting heart rate > 120 beats/min), a total of 31 patients of both sexes already scheduled for arterial catheteriza- tion were enrolled in the study. All patients gave their written informed consent, and the study protocol was approved by the local ethics committee. The investigational device The investigational device was a noninvasive sphygmo- manometer that recorded optical signals at the wrist using refection photoplethysmography [2]. The device con- sisted of an external silicone housing that encapsulated an