Accuracy of a wearable watch-type oscillometric blood pressure monitor in rest and ambulatory blood pressure measurements.

The aim of this study was to evaluate the accuracy of a watch-type oscillometric BP monitor HUAWEI WATCH D2 for rest and ambulatory BP measurements and compare with a conventional ambulatory BP monitor (A&D TM-2430, Tokyo, Japan). Subjects were recruited to fulfill the age, gender, BP and cuff distributions of the AAMI/ESH/ISO Universal Standard in the general population. Two cuffs of the test device were used for wrist circumference 13-16 (medium) and 16-21 cm (large), respectively. During the ambulatory validation study, subjects were asked to pedal at a low workload to elevate heart rate. For the 24-h ambulatory measurement, two BP monitoring devices were simultaneously worn on the same arm with the A&D cuff on the patient's left arm and the HUAWEI WATCH D2 on the left wrist. In the study on rest BP measurement, 95 subjects were recruited and 85 were analyzed. For validation criterion 1, the mean ± standard deviation (SD) of the differences between the test device and reference BP readings was -1.6 ± 6.4/-1.9 ± 5.0 mmHg. For criterion 2, the SD of the mean BP differences between the test device and reference BP readings per subject was 5.8/4.7 mmHg. In the ambulatory validation study, the mean difference between the device and observers was -0.9 ± 7.3 mmHg and -0.7 ± 4.9 mmHg for systolic and diastolic BP, respectively. We also compared the 24-h BP data with the HUAWEI WATCH D2 and cuff-based A&D in 35 adults. The mean difference (±SD) in systolic/diastolic BP between the device and A&D were -1.1 ± 6.3/1.0 ± 4.2 mmHg, -2.0 ± 6.5/-0.2 ± 4.7 mmHg and 1.2 ± 6.7/ 4.2 ± 4.4 mmHg for 24-h, daytime and nighttime, respectively. The watch-type oscillometric BP monitor HUAWEI WATCH D2 has met the requirements of the AAMI/ESH/ISO Universal Standard (ISO 81060-2: 2018/AMD 1: 2020) in both rest and ambulatory measurements. Moreover, the HUAWEI WATCH D2 achieved acceptable agreement with 24-h ambulatory BP measurement.