Real-time blood pressure monitor, non-invasive, using the ECG and photoplethysmography signals

• Grant number: 15/22659-0
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: July 01, 2016
• End date: June 30, 2017
• Field of knowledge: Engineering - Biomedical Engineering - Medical Engineering
• Principal Investigator: Sebastião Vagner Arêdes
• Grantee: Sebastião Vagner Arêdes
• Company: Aredes Equipamentos Hospitalares Ltda
• City: São José dos Campos

Abstract

The advance of technology in electronic healthcare equipment has increased the need to design non-invasive equipment to measure and monitor various types of physiological signals. Among the main vital signs, we can highlight the Electrocardiogram (ECG), the Blood Pressure (BP) and Photoplethysmography (PPG), which will be the focus for this research project. BP can be measured directly through the invasive catheterization of an artery attached to a pressure transducer, and indirectly, by non-invasive methods using, for example, ECG and PPG signals to detect systolic and diastolic pressures. The motivation of this project is the difficulty in determining the BP through a non-invasive method using the ECG and PPG signals, trusted to the actual value. The objective of this project is to develop a microprocessed system consisting of hardware, firmware and software to determine the BP through biomedical signs of ECG and PPG. The electronic system is comprised of a dedicated hardware for capturing electrical signals from electrodes (ECG) and sensors (PPG), which are received and processed by the microprocessor and sent to the PC to perform the processing of signals by filtering and capturing the main parameters of the signals, to finally calculate the systolic and diastolic pressures. The calculation of the pressures is defined by an algorithm which uses the parameters obtained from continuous and synchronized ECG and PPG signals and the calibration parameters, which main parameter is the time interval between the peak of the R wave of the ECG and half upper slope of PPG, called Pulse Wave Transit Time. Finally, it is expected to be achieved the main goal of this project, where the electronic system calculate the indirect method Blood Pressure, contributing to a new non-invasive method that uses physiological signals already known and with dominated features, where the main challenge is find the best parameters and constants for the algorithm calculating the systolic and diastolic pressures. The impact of this project in the scientific contribution to present a study and development of a method for calculating the Blood Pressure and user comfort when subjected to a procedure that requires multiparameter monitors, which reduces the number of sensors and wires connected to it. Thus, the method uses physiological ECG and PPG signals to calculate the BP, without the need of an inflatable cuff or cuff at constant pressure, which also causes discomfort to the user. (AU)