Enabling technologies for remote health monitoring

Abstract

Blood Pressure (BP) is one of the vital signs to measure health care of the personand it is useful to find out the cardiovascular diseases. Recent research showsthat measurement of BP using physiological parameters is gaining more interests.Current methods of measuring the BP are based on cuff based systems that areoften cumbersome and uncomfortable. The state of the art demands continuousmonitoring of BP using cuff-less devices employing non-invasive methods. Theaim of this work is to implement a wearable system that measures the BP basedupon physiological parameters: Pulse Transit Time (PTT) and Pulse Wave Velocity(PWV). By doing so, this enables a cuff-less and non-invasive method to measurethe BP. To obtain physiological parameters, we have used two physiologicalsignals that are Electrocardiogram (ECG) and Photoplethysmography (PPG). Wehave obtained ECG signal through single lead three electrodes along with an ECGfilter that is processed further in the microcontroller. In addition to this, a photodetecting sensor has been used to capture the Photoplethysmography (PPG) signalfrom the subject. These physiological signals have been further processedin a dedicated processor to measure Heart Rate (HR), PTT, and PWV. We havecalculated BP from different methods and the error analysis for all methods arepresented. Based upon the comparison of error for all methods, we have usedPulse Wave Velocity Peak (PWVp) parameter to derive BP. The error for SystolicBlood Pressure (SBP) is +11 mmHg to -12 mmHg and Diastolic Blood Pressure(DBP) measurement with PWVp based method is +10 mmHg to -14 mmHg incomparison to standard cuff based method. Further, ECG and PPG signals havebeen transferred to the smart phone over bluetooth to enable continuous remotemonitoring.