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Abstract: Numerical simulation of heating of the surrounding biological tissues by a transcutaneous inductive power transfer system with an output power of 500 mW has been performed. A four-layer skin–fat–fascia–muscle model of biological tissue and a model of the inductive power transfer system with three volumetric heat sources (transmitter coil on the skin, receiver coil and rectifier in the subcutaneous fat layer) were used. Six materials of the implant casing were tested: ABS plastic, polypropylene, polycarbonate, silicone, polyethylene terephthalate, and Y-TZP ceramic. It was found that Y-TZP ceramic provided minimum tissue heating (maximum increase in temperature, 1.6 °C); heating was maximum when polypropylene was used (maximum increase in temperature, 2.3 °C). PubDate: 2022-05-12
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Abstract: A laser technology for producing conductive film and bulk composites is proposed. The composites are made from calcium phosphate and albumin biopolymer permeated by a network of carbon nanotubes. Exposure of the areas of composite films produced from dispersions with nanotube concentrations of 0.1 and 1 mg/mL to pulsed radiation at a wavelength of 1064 nm made it possible to obtain the maximum conductivity of 21 and 100 mS·m−1 at a radiation power of 3 and 2.4 W, respectively. The maximum increase in the conductivity by a factor of 3.3 was obtained after laser treatment of a film based on a dispersion with the nanotube concentration of 0.1 mg/mL. The maximum number of percolation nodes in the bulk network of nanotubes in a dielectric matrix of calcium phosphate and albumin was achieved by exposure to continuous radiation with a wavelength of 810 nm and a power of 9 W for 80 minutes. The conductivity of composite films was close to that of human cortical bone, while the conductivity of bulk composites exceeded that of human cortical bone by 3-4 orders of magnitude. The technology presented in this work can find application for the cultivation of bone cells and/or regeneration of bone tissues by electrical stimulation. PubDate: 2022-05-12
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Abstract: A universal design of a pediatric hydrodynamic bench for testing various techniques of mechanical circulatory support has been developed. The bench provides high-accuracy simulation of the basic hemodynamic parameters of the pediatric circulatory system under normal conditions and heart failure. The hydrodynamic bench was used to simulate the interaction of the left and right ventricles of the heart with an implanted pediatric axial pump under conditions of heart failure. PubDate: 2022-05-12
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Abstract: Results of design studies of individual prostheses of the wrist’s radius bone are presented. The aim of prosthetization was to replace damaged bony tissue. The results of this study are compared with expected outcomes. PubDate: 2022-05-12
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Abstract: An original cardiac resuscitator has been developed within the framework of developing a mobile automated system for cardiopulmonary resuscitation. Its operation in combination with a mechanical ventilator has been tested. The control system and the control panel of the resuscitation system have been designed. The results of testing of the resuscitation system are presented. The advantages of the system over its foreign counterparts are described. PubDate: 2022-05-12
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Abstract: Fluid flow in a hydraulic test system was visualized. The test system was used to simulate the flow through an improved modification of the Sputnik LVAD. The experiments were run in three operating modes with different volumetric flow rates and identical pressure heads (80 mm Hg): the nominal mode (4.5 L/min), a low volumetric flow rate mode (3 L/min), and a high volumetric flow rate mode (6 L/min). The study showed that the fluid flow velocity field in the modified pump was highly stable in all areas under study. Comparison of the original and modified impeller designs showed that the optimization was successful. Further tests should be carried out to check the LVAD safety and hemolysis. PubDate: 2022-05-12
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Abstract: A method for personalized analysis of the stress−strain curve of the endo-prosthetics subsystem of an endo-exo prosthetics system implanted into the femoral medullary canal is presented. The method is based on the analysis of CT scans. The results of test application of the method are presented. The goal of the study is to determine the reliability and the strength margin of the implant−bone system under conditions of osseointegration in a walking patient. The study has shown that the bone density is sufficiently high to meet the requirements for the endo-exo femur prosthesis; the strength margin of the bone is 11.5. PubDate: 2022-05-12
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Abstract: The possibility of automating two-stage blood transfusion (including biological testing and transfusion proper) was evaluated. The calculated and actual transfusion rates were compared. Fifteen red blood cell units were transfused. Transfusion of red blood cells using an infusion pump, standard blood transfusion lines, and warming devices allows: a) eliminating the subjective factor in selecting and implementing the transfusion mode; b) automating both preliminary biological testing of blood and transfusion proper; c) warming the transfusion medium before transfusing it into the donor’s vein; d) preventing hemolysis during transfusion. PubDate: 2022-05-12
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Abstract: The problem of surface electromyography signal processing for the purposes of control of robotic devices such as prostheses and manipulators is considered. An algorithm for estimating the level of nerve excitation is proposed, as well as an adaptive algorithm for estimating the activation level. Calculations and tests showed that the proposed method allows obtaining control signals with the shortest response time. PubDate: 2022-05-12
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Abstract: Near-infrared spectroscopy continues to be a method with great potential for developing noninvasive devices for monitoring blood glucose in patients with diabetes mellitus. This article discusses the main problems hindering creation of accurate noninvasive sensors, which are linked mainly with difficulties in mathematical modeling of the distribution of irradiation in biological tissues and the need for improvements to the component basis for designing portable devices. Current approaches to improving measurement systems and mathematical systems for computing glucose concentrations are reviewed. PubDate: 2022-05-12
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Abstract: Different approaches to the implementation of photocatalytic elimination of urea in aqueous solutions are considered. The main advantages and drawbacks of the photocatalytic method as compared with existing methods for dialysate regeneration are presented. The potential for using the photocatalytic method for urea elimination in wearable artificial blood purification devices is described. PubDate: 2022-05-12
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Abstract: A review of devices for detecting human muscle activity by surface electromyography is presented. The focus is on ready-for-use circuit solutions for EMG sensors for medical investigations from Elemyo (Russia), Grove (China), and CT Retail (China), which are available on the current electronics market. The technical characteristics of modules are analyzed and results obtained by detection of muscle activity on flexion and extension of the hand joints to form a fist are presented. It is concluded that these EMG sensors have potential for use in bionic hand prosthesis control systems. PubDate: 2022-05-12
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Abstract: This study uses computer modeling to assess the potential of using certain biocompatible polymer materials in coronary stent-grafts. Numerical experiments were carried out to assess mechanical properties of samples of polymer materials: hydrogels based on polyvinyl alcohol or polylactide–polycaprolactone copolymer. The studies showed that when the stent-graft membrane was free to move, all the materials showed similar shortening, with changes in diameter of 7.21-7.63 mm from the initial 20 mm (36.05-36.6%). This was accompanied by thinning of the component by 34-37%. When the membrane was fully fixed to prevent shortening, the decrease in thickness was greater – by 53-61% – and was accompanied by a significant increase in stress (for one polylactide–polycaprolactone copolymer it reached 44.37 MPa, which is close to the tensile strength of the material, 47.07 MPa). These results show that three of the studied materials have potential for use in coronary stent-grafts: two modified hydrogels based on polyvinyl alcohol and a polylactide–polycaprolactone copolymer. PubDate: 2022-05-12
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Abstract: The electrochemical processes occurring on electrodes in cardiac pacemakers were considered. A method for calculating transient processes and the associated integral indicators of current delivery to cardiac tissue, i.e., impedance, residual polarization voltage, electrical capacity, and charge transfer efficiency, was proposed. Model experiments were performed to test coatings made of different materials. The study results can be used in designing up-to-date cardiac pacemaker systems. PubDate: 2022-05-12
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Abstract: An optoelectronic spectral system was developed for monitoring the elimination of uremia markers of low and middle molecular weight during hemodialysis therapy by measuring UV absorption at 285 and 365 nm. The elimination kinetics of AGE products were analyzed using a two-pool model in comparison with the conventional markers for dialysis adequacy. These studies showed that monitoring of optical absorption at 365 nm could be used as an alternative method for assessing hemodialysis adequacy. PubDate: 2022-05-12
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Abstract: We present here a new concept in design of intelligent self-moving adaptive upper limb prostheses based on a manipulator robot of parallel structure implemented as an octahedral dodecapod. The principles of the robot construction are described, these providing self-driven motion and self-installation on the stump regardless of the level of amputation, high specific rigidity, and reliable grasping of objects regardless of their geometrical shape, size, and the physical properties of the materials of which the objects are made. Examples of the possible applications are presented in physical prosthesis models. PubDate: 2022-05-12
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Abstract: Different approaches to correction of the ECG signal baseline drift are compared. A new adaptive method for correction of the baseline drift is proposed. The method is based on shaping the reference signal of the adaptive filter using multiresolution wavelet transforms of the ECG signal. Different baseline drift correction methods are compared in terms of their efficiency for processing model ECG signals contaminated by baseline drift of various intensities. The accuracy of determining the ST-segment deviation in real ECG signals using different methods for the baseline drift correction is assessed. PubDate: 2022-03-07 DOI: 10.1007/s10527-022-10149-8
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Abstract: The use of laser flow cytometry and light microscopy for assessing the effect of treatment of acute megakaryo-blastic leukemia is considered. Bone marrow has been tested in child patients aged three months to eleven years undergoing treatment at the N. N. Blokhin National Medical Research Center of Oncology. The capabilities of morphological diagnosis and flow cytometry for assessing the minimal residual disease in acute megakaryoblastic leukemia in children have been elucidated. PubDate: 2022-03-05 DOI: 10.1007/s10527-022-10142-1
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Abstract: Shortcomings of the previously proposed method for calculating the total filtration of the X-ray beam, the first and second half-value layers, and the radiation homogeneity coefficient from the radiation spectrum of the X-ray machine are identified. An improved modification of the method is proposed. The calculation procedure and formulas are described, and their applicability for processing experimental data is evaluated. It is shown that the use of the proposed modification of the method allows reducing the maximum differences between the experimental and calculated values of the radiation parameters of the X-ray machine. PubDate: 2022-03-05 DOI: 10.1007/s10527-022-10147-w
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Abstract: The article considers problems of synthesis of hybrid fuzzy decision rules for the knowledge base of an expert system used by occupational physicians treating electric power industry workers. A method for the synthesis of the expert system decision rules has been proposed and tested in patients with immune diseases. PubDate: 2022-03-05 DOI: 10.1007/s10527-022-10154-x
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