Continuous blood pressure monitoring using pulse wave delay

Proposed paper is a part of a research to develop a convenient method for continuous monitoring of blood pressure by non-invasive and non-oscillometric way. The method is based on a presumption that there is a singular relationship between the velocity of pulse wave and blood pressure for a person. The detection of the velocity of pulse wave is based on the registration of the mechanical movements of blood vessel´s walls and computing the time delay in different regions of the human body using an ECG as a reference signal. Additional information about the blood pressure evaluation is gotten from the photoplethysmographic (PPG) channel. Used optical method, which is able to detect pulsation profiles of the blood vessels, is based on the self-mixing that occurs in the diode laser cavity when the radiation, scattered back by the skin into the laser, interferes with the field inside it and causes the changes of the laser pump current. National Instruments software LabView for Windows is used for output signal digitalization and processing purposes.