GENERATION MECHANISMS OF SHUNT MURMURS USING FINITE ELEMENT METHOD

Abstract

At present, stethoscopy represents the only convenient and noninvasive method of assessing shunt function, but lacks quantifiability and objectivity. Therefore, as a new technique for assessing blood access function, we investigated techniques for analyzing shunt murmurs based on wavelet transformation. Results obtained using this technique were comparable to those obtained by stethoscopy and favorably represented blood flow in the shunt of dialysis patients. As few reports have described shunt murmurs and the mechanisms of onset have not been clarified, we attempted to clarify the mechanisms of onset underlying shunt murmurs using the finite element method (FEM). The present report describes the results of FEM analysis using an artificial blood vessel. High-accuracy FEM analysis requires preparation of an accurate FEM model and then simultaneous fluid analysis of blood components and structural analysis of vessel components. Since these results need to be related mutually, the fluid-solid interaction function of general-purpose FEM software was utilized. For analysis of conditions, material constants of the artificial blood vessel were determined based on measurements obtained using a microhardness tester, while inflow conditions were determined based on radial artery measurements obtained using an invasive sphygmomanometer. The results of FEM analysis broadly matched the clinical data.