An Ambulatory Blood Pressure Monitoring System Based on the Uncalibrated Steps of the Wrist

Hypertension has become the most common chronic disease which brings a heavy medical burden to society. However, current intermittent measuring instruments, such as electronic sphygmomanometer, cannot monitor blood pressure (BP) in real time. At the same time, there are calibration steps in ambulatory measuring instruments represented by pulse arrival time (PAT)-based measuring instruments, which are inconvenient for patients. In order to overcome the above mentioned shortcomings, this study developed a wrist-based wearable real-time measurement system without calibration steps. Based on the hemodynamic principle of the linear relationship between the waveform parameters of Photoplethysmography (PPG)-Ballistocardiography (BCG) and BP, the systolic and diastolic blood pressure prediction results of this device had a correlation coefficient of 0.9 and 0.92, respectively, compared with the actual values. The MAD and RMSE were 3.08 ± 4.29 mmHg and 1.52 ± 2.20 mmHg correspondingly, which was superior to traditional PAT-based BP prediction devices. The results showed that the device has the advantages of simplicity and accuracy, which helps to improve the quality of life for patients and reduce the medical burden caused by hypertension.