PS-BPC03-1: DEVELOPMENT OF CUFFLESS AND CALIBRATION-LESS BLOOD PRESSURE MEASUREMENTS

Abstract

Objective: The characteristics of dynamic short-term blood pressure variability caused by numerous triggers vary greatly among individuals. Wearable devices that continuously and noninvasively capture beat-by-beat blood pressure values are a necessity to further study blood pressure. The development of cuffless blood pressure measurements, which, unlike sphygmomanometers, do not require pressurization and depressurization time, has attracted much attention in recent years for its potential to capture beat-by-beat blood pressure values. However, cuffless blood pressure measurements approved in Europe and the United States require calibration before use. This indicates that the function is limited to estimation of blood pressure variation from the time of calibration. In this study, we conducted a measurement test aiming at the practical application of the cuffless and calibration-less blood pressure measurements. Design and Method: In this study, we recruited adults aged 20 years and older to evaluate whether a wearable device without pre-calibration could meet the standards of BHS, ESH, ISO81060–2:2018 and IEEE1708a-2019 and ensure the same accuracy as existing sphygmomanometers. For each measurement test, the cuff was wrapped around the subject's upper left arm and a wearable device was attached to the ipsilateral wrist, and the subject was asked to maintain a sitting posture. Measurements were taken with the reference sphygmomanometer every 3 minutes for 7 times. To minimize the effect of the venous congestion on the measurements, the measurement period with the wearable device was from 30 seconds after the completion of the cuff depressurization until the start of the next pressurization. The blood pressure value measured by the wearable device was evaluated against the average of the values measured by the reference sphygmomanometer before and after. Results: 219 participants were included in the analysis. Participants with systolic blood pressure values ranging from 80 to 204 and diastolic blood pressure values ranging from 46 to 140 were included. The mean and SD of the differences between the estimates and the reference were -1.27 ± 4.97 mmHg for SBP and 0.74 ± 2.55 mmHg for DBP. Conclusion: The overall accuracy of the cuffless and calibration-less blood pressure measurements device satisfied the criteria shown in ISO81060–2 against various adults in the sitting posture. This study showed the strong potential of the cuffless and calibration-less blood pressure measurements.