Postural Stress Tests for Evaluation of Pulse Wave Propagation Time Based Method for Indirect Blood Pressure Measurement

摘要

Blood pressure is not a constant, it is continuously changing value which could go beyond of the physiological norm. This phenomenon is called the variability of blood pressure allowing to track changes in the circulatory system functioning. Recently, the interest in indirect methods and systems for blood pressure measuring has grown significantly because of their prospects. This paper reviews the Frank's Windkessel model, which describes the interaction of blood pressure and pulse wave velocity. The simultaneous effect of changes in blood pressure and quasiperiods imitating heart rate on changes in pulse wave propagation time is studied. The obtained simulation output have been used for testing of the method of indirect evaluation of blood pressure. To perform some experiments for checking correlation between BP and pulse wave propagation time was developed computerized system for the dynamic orientation of the human body for postural stress tests. The system includes a special mechanical table with equipment for distal fixation of the patient's body to provide movements of a person at different speeds along three orthogonal axes, and a hardware-software complex for recording and displaying in real time an electrocardiogram, rhythmogram and the patient's movement in three-dimensional space.