Vol 51, No 3 (2017)

Magnetometric systems based on superconducting quantum interference devices (SQUID) were developed for bio-medical applications. The characteristics of existing SQUID systems that can be used in magnetocardiography (MCG) are discussed. The results of clinical MCG studies of a group of volunteers with paroxysmal atrial fibrillation and a group of apparently healthy persons are presented as an example.

In this paper, the use of a magnetometer based on iron garnet films for magnetocardiographic measurements is described. All measurements were performed at room temperature, without sensor cooling. A map of the three orthogonal vector components of the magnetic field of the human heart was obtained.

Acellular dermal matrixes (ADM) for reconstructive surgery were made by treating skin samples from rats and humans with sodium dodecylsulfate (SDS), sodium deoxycholate (DOC), saponin, and DNase. A mixture of SDS and DOC removed cell residues effectively, though the ADM had cytotoxic properties. After treatment with 2% DOC, there was no cytotoxic effect and the resulting material contained 27-202 ng/mg dry weight DNA and from 0.07 to 2.6% fat, depending on the source of the samples.

The results of experimental studies of temperature fields in the near-surface areas of mineralized biological tissues during and after hydrodynamic separation are considered. Temperature fields were recorded by contactless methods.

Atrial fibrillation (AF) is the commonest arrhythmia seen in clinical practice, though our understanding of the mechanisms of its generation, propagation, and reinitiation remains incomplete. This is limiting not only from the scientific point of view, but also from the practical, as regulatory documentation for the treatment of this pathology cannot be developed without an accepted theory. There has been a recent increase in interest in a theory based on the observation that spiral waves, or rotors, with specific properties for each atrium, are the source of the trigger for fibrillation and may therefore serve as targets for radio-frequency treatment in low-invasive endocardial procedures. There is also an approach based in seeking areas of the atrium in which complex fractionated atrial endograms (CFAE) can be recorded. We present here the basic concepts of analysis of atrial signals during atrial fibrillation, reflecting both the technical and medical aspects.

We report here studies of the properties of a new type of plasmatron with long-lifetime operation and an ultrapure plasma jet investigated using emission spectroscopy, thermal imaging, and chemical sparging. Results of measurements of the concentrations of the chemical radicals NO and NO₂ and the distribution of the gas temperature close to the plasma jet, which determines the potential for using the plasmatron in medicine, are reported.

The goal of this work was to improve the efficiency of early detection of microcalcifications, the earliest indicators of breast cancer. Studies have shown that the presence of isolated clustered microcalcifications in the mammary gland significantly increases the range of variation of effective atomic number and considerably changes its distribution. Conventional, subtraction, or dividing mammography or their linear convex combination may fail to visualize isolated clustered microcalcifications. However, the presence of microcalcifications in the mammary gland can be determined analytically from the distribution of the extreme terms of an ordered series of effective atomic numbers in the mammary gland. Then, the coordinates of the isolated clustered microcalcifications can be calculated. The distribution of the effective atomic numbers in healthy tissue without microcalcifications is symmetric and close to normal, while breast tissue with even a single isolated cluster of microcalcifications is characterized by an asymmetric distribution and high values of the maximum effective atomic numbers. An algorithm for calculating the coordinates of isolated microcalcifications is suggested.

The article demonstrates how to build, on the basis of readily available components, a high-frequency driving generator for high-intensity focused ultrasound transducers used for experimental tissue ablation and vessel obliteration.

A method for assessing the blood clotting system in pregnant women using a fuzzy classifier is described. Informative parameters were identified. Use of a gravitational algorithm for optimizing the parameters of the fuzzy classifier is described. Test results are presented.