| Hemodynamic monitoring is a highly valuable guidance during observation, diagnosis, and treatment of cardiovascular diseases. While most hemodynamic monitoring systems today entail routine measurement and display of blood pressure or other arterial waveforms, more effective systems are demanded by a fast growth in the proportion of the elderly population and a major shortage of clinical staff projected over the next decade. To this end, novel techniques based on impulse response estimation are presented in this dissertation to continuously monitor cardinal hemodynamic variables by mathematical analysis of cardiovascular waveforms measured with instrumentation already in use or available.;Techniques based on the Windkessel model were proposed to continuously estimate cardiac output and left atrial pressure from peripheral arterial blood pressure, pulmonary artery pressure, and right ventricular pressure waveforms respectively. Long time interval analysis was applied in these techniques to circumvent the wave reflections and inertial effects in the blood pressure waveforms. The techniques were evaluated with animal/human experiments and showed application potential in clinical practice. Efforts were further made to extend the long time interval analysis technique to the photoplethysmography waveform and pilot results confirmed the feasibility.;Techniques for robust estimation of the pulse wave velocity were developed in order to achieve accurate arterial stiffness and cuff-less blood pressure monitoring. System identification methods using both physiologic-based and black-box models were employed to improve the robustness of the techniques. Preliminary results obtained from animal/human experiments demonstrated potential clinical values of the techniques.;With further evaluation, these techniques may ultimately be employed conjunctively to arrive at continuous and effective hemodynamic monitoring systems in various clinical settings. |
