Determination of the Thickness of Biological Tissue through a Multilayer Model of Acoustic Pressure

The diabetic foot is a disease that occurs as a result of diabetes mellitus (DM). This problem is caused after suffering by a long time from this pathology. The appearance of the diabetic foot can be prevented and combated through measurements and tracking of the physical characteristics of the tissues that compose the foot of the patient with DM disease. Some of those physical characteristics of the foot could modify the expected tissue thicknesses of the foot layers compared to those in healthy subjects. This article presents a multilayered numerical model of acoustic wave propagation in biological layered tissues with ideal thicknesses and geometry; the finite element method was used to study the behavior of echoes of ultrasound waves on each of the layers of the model. In this work, a non-invasive broadband ultrasonic pulse is applied on the layers of the tissues of a foot, to determine the already known thicknesses and evaluate the capabilities of this approach to detect possible thickness variations. With the detection of small differences, it will be eventually possible the early detection of patients with the possibility of suffering from diabetic foot disease. The results indicate that the average of the percentages of relative error observed in the determined thickness of each of the layers, using cross-correlation, does not exceed 5%, which allows the validation of our technique as a tool for detecting thickness variations.