Analyzing wall thickness of artery phantoms in a noninvasive way

Research looking for the achieving of an accurate measurement of thickness changes in thin biological walls (e.g. of blood vessels), is a promising work line in the medical area, because it would provide the bases to analyze the possibility of attaining early diagnoses of some diseases such as hypertension or atherosclerosis. But, to obtain a non-invasive estimation of these parameters on internal tissues, currently presents many difficulties that must be overcome. The use of high-frequency ultrasonic systems appears to offer a possible solution. In fact, the application of conventional ultrasonic imaging has shown this, but the spatial resolution related to this commercial option is not sufficient for a thickness evaluation with sufficient clinical significance, which would require accuracies of few microns. In this paper, some preliminary results of applying a new broadband ultrasonic procedure, recently developed by the authors for thickness measurement purposes, are analyzed for sub-millimeter layers made of materials similar (phantoms) to that of the biological tissues to be encountered into the artery walls. Two optional algorithms for estimating the power spectral density of the multi-pulse signals are assessed with some experimental echoes. Their potential resolutions and capabilities to provide accuracies around a micron are comparatively analyzed, for walls thickness estimation.