Near-field resonant microwave sensing in the diagnostics of bovine mastitis

Abstract

The purpose of this work is to analyze the possibilities of evaluating the dielectric parameters of the mammary gland of cows in the diagnosis of mastitis. The study was performed on animals from a number of farms in the Nizhny Novgorod and Kirov regions. A total of 269 mature cows were examined, 185 of which were healthy, 53 individuals had subclinical mastitis, and 31 had a clinically manifested form of the disease. The animals were examined once, by instrumental analysis of the dielectric parameters of the tissues of each lobe of the udder of the animal. The study was carried out using a software and hardware complex, which makes it possible to evaluate the dielectric permittivity of a biological object by the method of near-field resonant microwave sensing. As a result of our research, we have for the first time formed a physiological “pattern” of the dielectric permeability of the skin and breast tissues of actively lactating cows, taking into account the features of the morphological structure of the udder at a significant depth of subsurface sounding (20 mm). It was found that the presence of a focus of inflammation (both in the form of subclinical and manifesting mastitis) leads to a significant increase in dielectric constant (by 12.4 and 26.9%, respectively). At the same time, in healthy cows, the hydration level of tissues of various udder lobes is almost uniform, as evidenced by the values of the dielectric gain coefficient close to one. In the case of the formation of a mastitis focus in one or some parts of the udder, uniformity is violated, and the dielectric constant gradient can be up to 31% with a corresponding increase in the developed coefficient.