Document Type
Thesis
Date of Award
5-31-1987
Degree Name
Master of Science in Biomedical Engineering - (M.S.)
Department
Biomedical Engineering Committee
First Advisor
David S. Kristol
Second Advisor
Peter Engler
Third Advisor
Swamy Laxminarayan
Fourth Advisor
Shlomo Gabbay
Abstract
The design and development of a pulse duplicator system for testing of prosthetic valves is described. The performance characteristics were evaluated by computing the input impedance of the system from the measured pressure and flow signals for different simulation configurations. The study has been further extended to determine the feasibility of evaluating the cardiovascular status of a patient after major open heart procedure or in state of shock.
Built on hydrodynamic principles, the model allows for a wide range of heart rates, flow rates and mean pressures to be simulated. The artificial circulatory system used as a load to the heart is generated by a lumped parameter 3-element windkessel model. It consists of two hydrodynamic resistors representing the peripheral resistance Rp and the characteristic impedance of the aorta Rc, and the compliance chamber representing the total arterial compliance.
The hydrodynamic resistors Rp and Rc were constructed using polyethylene tubes arranged in a parallel configuration. The respective number of tubes for Rp and Rc were 512 and 3640 with tube lengths of 12.2 and 6.5 cms and diameter .058 cm. The design parameters were chosen to achieve mean systemic pressures of upto 150 mm Hg and mean flows of 125 ml/sec.
The generated pressure and flow waveforms in the left ventricle and the ascending aorta simulate the physiological shapes very closely. Some oscillations do occur in the aortic pressure waveform immediately upon valve closure. The input impedance spectra show excellent agreement with the theoretical spectra of the proposed model for the in vivo systemic circulation.
Recommended Citation
Kadam, Pankesh Nilkamal, "Characterization of pulse duplicator model for testing of heart valves" (1987). Theses. 3124.
https://digitalcommons.njit.edu/theses/3124
