A new method based on aortic pressure wave decomposition successfully identified arterial reflection sites and aortic occlusions in dogs with a spatial resolution of approximately 0.1 m.
We developed a new method to determine the location and importance of reflection sites in the arterial system. The method is based on the decomposition of the aortic pressure wave into its forward and backward components, and it provides the reflection profile of the arterial system as a wave reflection site amplitude versus distance from the heart. The reflection profile can be seen as the response of the arterial system to a pressure delta pulse where reflections upstream from the measurement location have been eliminated. The method was successfully tested on a simple model loaded with a pure resistor, a two-element windkessel, and a bifurcating tube system. It was then applied to the aortic pressure and flow signals measured in six mongrel dogs whose aorta was occluded at different levels. The profiles obtained from measurements at control showed two main reflection regions, one located in the vicinity (0.1-0.2 m) of the heart and the other located in the region of the iliac bifurcation. All occlusions, even the most distant one at the iliac bifurcation, could be identified in both amplitude (amount of reflections) and distance from the heart. The spatial resolution of the profiles was approximately 0.1 m as a result of the limited power spectrum contained in the arterial pulse, and the identification of reflection sites decreased rapidly with the distance.
Pythoud et al. (1996) studied Arterial reflection sites (n=6). New method for determining distribution of reflection sites was evaluated on Identification of reflection sites in amplitude and distance from the heart. A new method based on aortic pressure wave decomposition successfully identified arterial reflection sites and aortic occlusions in dogs with a spatial resolution of approximately 0.1 m.