The relation between the pressure drop and flow of a uniform segment of blood vessel is shown in the Figure in the box. The relation consists of a longitudinal impedance, which is described by Womersley’s oscillatory flow theory [1, 2], and a transverse impedance , describing the pressure-area (or volume) relation of the segment. The combination of longitudinal and transverse impedances gives characteristic impedance and wave propagation (Appendix 4).
- 2.Womersley JR. The mathematical analysis of the arterial circulation in a state of oscillatory motion. 1957, Wright Air Dev. Center, Tech Report WADC-TR-56-614.Google Scholar