Vol 53, No 1 (2019)

The article presents the results of an experimental comparison of the accuracy characteristics of contactless photoplethysmographic systems. The hardware of the experimental setup, the principle of the software operation, the measurement technique, and the results of the comparative study are described.

An improved optical coherence tomography system equipped with an endoscopic probe is presented. A key feature of the described device is the possibility of high-precision positioning of the endoscopic probe. This effect is achieved by the use of microelectromechanical systems for assessing the angular velocity and acceleration. The scanning process is optically synchronized with the process of calculation of the spatial coordinates of the endoscopic probe. The expediency of using the developed system for real-time evaluation of the biomechanical properties of blood vessel walls or their phantoms is discussed.

A device for investigating blood pressure in the intramural vessels of hollow organs and determining arterial blood hemoglobin oxygen saturation was developed; the device consists of two chambers, one containing LED lamps and the second, an emitter for determining blood oxygen saturation.

An original method of determining placental volume by 3D modeling of the results of ultrasound placentometry is presented. Calculations and methods for creating 3D models of the placenta are given and the effectiveness of using this method for measurement of placental volume is assessed.

A hardware and software system for extracorporeal detoxification of blood plasma was developed. The effectiveness of the air barbotage technique for removing carbon tetrachloride from blood plasma and its mixtures with plasma substitutes was investigated. The detoxification efficiency was shown to depend on the characteristics of the obtained foams, including the foam-forming ability, froth factor, dispersity, foam scaffold stability, and syneresis. The program for monitoring and control of extracorporeal detoxification of blood plasma was tested. Physical and mathematical models of toxicant excretion in the process of extracorporeal blood purification were elaborated. The mathematical model was verified; the theoretical and experimental data were shown to be in good agreement.

In this article, an electrical equivalent circuit for simulation of the response of various tissues of the human body to electrosurgical treatment is proposed. The circuit can be used to optimize the output characteristics of electrosurgical devices.

The aim of the present work was to develop a device for semiautomatic manipulation of an optical light guide for laser proctology solving the problem of increasing the accuracy of light guide positioning in low-invasive proctological laser operations using a laser coagulator for the treatment of vascular and oncological diseases. The proposed technical solution increases positioning accuracy by manipulating the optic light guide with a device with two degrees of freedom, firmly attached to the proctoscope, with adjustment of the angle using a lever mechanism and linear semiautomatic movement of the optical light guide using stepper drives. Preclinical and subsequent clinical trials of the device for laser coagulation are planned.

Thermal radiation by the multilayered structure of the part of the body containing the kidney was modeled for adaptation of waveguide antennas developed for use in breast examination to use in urology. These calculations confirmed the possibility of using microwave radiometry to detect vesicoureteral reflux and other renal pathologies.

The potentials of using various physical principles of feedback in fiber laser-based surgical systems were investigated. Different ways of providing feedback by recording and analyzing signals received from the tissue area exposed to fiber laser radiation were proposed and studied. These signals include the glow signal and the mechanical resistance to the optical fiber exerted by the tissue in the process of laser perforation. The dynamics of feedback signals during perforation of composite model samples consisting of biomodels and biotissues of various types was studied. The difference in the signals detected in different biomodels exposed to fiber laser radiation can be used for real-time differential diagnosis of evaporated biological tissues.