A MODIFIED METHOD OF ARTERIAL ELASTICITY INDEX INCLUDING EFFECTS OF CONSTRAINTS FROM SURROUNDING TISSUES

摘要

Previously, we proposed an estimation method of arterial elasticity index (E_M) independent of geometric factors such as the radius and wall thickness. Since the previous method was based on an equation of a motion that assumed a thin cylindrical model with infinite length, it is thus necessary to account for the effects of dynamic constraints from surrounding tissues. The purpose of this study is to propose a modified method for quantifying arterial elasticity index accounting for the effects of dynamic constraints. We describe the modified method by vibration analysis of a thin cylindrical shell using a natural frequency depending on boundary conditions. To examine the feasibility of the proposed method, we measured the inner pressure, radius and natural frequency of the mock-vessels with dynamic constraints. From these results, the elasticity index (E_M) was derived independent of the effects of dynamic constraints. In summary, the proposed method enabled to derive elastic properties of arteries accounting for the effects of dynamic constraints in mock-vessels with both ends restricted.