P801Continuous cuff-less blood pressure monitoring using vascular elasticity model on photoplethysmogram

Background Hypertension is a well-known risk factor for potentially cardiovascular diseases, which is underdiagnosis and treatment. Clinical evidence suggests that periodic and continuous monitoring of blood pressure (BP) is helpful for the early detection of hypertension to reduce the cardiovascular risk. Photoplethysmogram (PPG) is a simple and non-invasive technique to measure the instantaneous blood flow in capillaries. This study proposes a miniaturized PPG sensor, which is feasible to integrate into smartphone, to estimate cuff-less BP and heart rate (HR). Methods A miniaturized PPG sensor, provided by FocalTech Smart Sensors Co., Ltd., was used to collect reflective finger PPG signal. The methodology of BP estimation from PPG was using a vascular elasticity model which estimating the physiological parameters from PPG features Simultaneously, we utilized oscillometric blood pressure monitors to obtain automated BP readings as the validation standard. Result Seventy-one subjects were recruited in this validation study. By using our PPG algorithm, an accuracy of ± 11.9 mmHg for systolic BP and ± 8.0 mmHg for diastolicBP was observed at 71 subjects. There was a good linear correlation (CC) between PPG-estimating BP and automated BP (systolic BP, CC=0.4; diastolic BP, CC=0/.45).Likewise, slopes of the liner fit on the Bland Altman plots for both systolic BP (slope = −0.23) and diastolic BP (slope = −0.11) indicated there was no particular bias in predicting high or low BP. Subjects characteristics Parameters Total number (subjects) 71 Entry BP range Normal 21 Prehypertension 27 Stage 1 hypertension 17 Stage 2 hypertension 6 Sex Male 37 Female 34 Age (years) Mean ± standard deviation 55±12 Range 27–77 Conclusion In this study, the feasibility of mobile based cuff-less BP measurement using a vascular elasticity model on finger PPG signal was demonstrated with a level of acceptable accuracy. Based on mobile-based and easy-to-use features of our sensor/device, the incorporation this real-time measurement into the monitoring of BP could be helpful for the management of hypertension.