A Novel Wide-Band Reflection-Based System for Measuring Abdominal Fat in Humans

Abstract

A Wide-Band (WB) radio frequency (RF) system has been thoroughly developed in order to measure the Subcutaneous Fat (SF) thickness in the abdominal region of humans. Recent conducted research has shown that the SF thickness is related to the thickness of internal fat called Visceral Fat (VF), which has important health implications, and therefore cannot be measured accurately by non-invasive techniques. Thus, this proposed non-invasive RF system offers the possibility of measuring the SF thickness and then estimating the VF thickness. The investigation details work carried out to optimise the penetration depth and the range resolution. These considerations resulted in a Gaussian pulse with a 1.45 GHz centre frequency and 462 MHz bandwidth being selected for the system. This has been implemented using an accurately designed compact antenna based on double-ridged horn (DRH) inside a high-permittivity material, which has been designed using the CST Microwave Studio (MWS) software. The employed abdominal model consisted of three layers: skin; fat, and muscle. The WB pulse has been directed at the model, and the reflections recorded for several SF thicknesses, including an infinitely thick layer, which provided the reference system pulse to compare the other cases with. This successfully demonstrated the principles of the system operation, with SF thickness of 10 to 30 mm being accurately measured, based on amplitude variations and also time shifting, in the proposed RF system.