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Vol 52, No 5 (2019)
- Year: 2019
- Articles: 16
- URL: https://journals.rcsi.science/0006-3398/issue/view/14654
Theory and Design
Studies of the Electrochemical Properties of Thin-Film Materials for Coating Cardiac Stimulator Electrodes
Abstract
The frequency characteristics of the admittances of a series of candidate materials for coating pacemaker electrode poles were studied. A method for assessing the properties of current transfer from an electrode connected to a source of stimulatory impulses to tissues is described. The main factors influencing decreases in the effectiveness of this transfer are identified. Potential physical vapor deposition technologies for depositing coatings, followed by alloying of films with metal ion beams, which increase the production of charged particles on the surfaces of the poles, are presented.
291-295
Article
A Mathematical Model for the Action of High-Frequency Currents on Biological Tissues
Abstract
An analysis of the actions of high-frequency currents on biological tissues is presented and an applied mathematical model of electrosurgical actions is proposed for studying coagulation by correlation with the parameters of the high-frequency generator at the moment of tissue coagulation.
296-300
Electrical Stimulation of Human Connective Tissue Cells on Layers of Composite Structures with a Nanocarbon Framework
Abstract
A technique for electrical stimulation of growth of connective tissue cells on composite structures with a nanocarbon framework was developed. Cells were stimulated with pulsed electric signal (amplitude, 200 mV; pulse duration, 2.5 ms) for 5 h. A study of the effect of the electrical stimulation on the viability of cells showed an increase in the proliferative activity and in the density of cells adhering to the surface of composite structure layers. The aspect ratio for the cell structure subjected to the electrical stimulation was 1.4 times greater than for nonstimulated cells. The developed technique can be used in tissue engineering, an important branch of regenerative medicine.
301-304
Plasma Glow Discharge as a Tool for the Dissection and Coagulation of Biological Tissues
Abstract
We present here the results of studies of the mechanism of plasma formation and the kinetics of plasma glow discharge required for making electrosurgical instruments with controllable plasma temperature. Numerical data on the energy parameters of the high-frequency current required for stable heating of the plasma glow discharge at atmospheric pressure are presented. Scientifically based technical solutions for creating prototype high-quality electrosurgical instruments with controlled-temperature low-temperature plasma glow discharge are described. The value of using a single technical platform based on a modular design for the main functional elements of high-frequency electrosurgical instruments with biological tissue dissection and coagulation modes based on temperature-controllable plasma glow discharge is assessed.
305-310
Channel Rotor Calculation for a Centrifugal Blood Pump
Abstract
A test model of a centrifugal pump with constant cross-section channels in the rotor was developed using 3D computer simulation. The channels are shaped as a logarithmic spiral. The geometry of the flow channel providing optimal flow in the nominal operating mode (flow, 5 L/min; pressure drop, 100 mm Hg) was calculated. In addition, pump operation conditions in the extracorporeal membrane oxygenation (ECMO) mode were considered. The main requirements imposed on the developed test model were those of meeting the allowable shear stress threshold and minimizing the stagnation and flow recirculation zones.
311-315
Measurements of Ion Beam Composition in the Temporary Radiobiology Facility at the Institute for High Energy Physics
Abstract
A detector consisting of four p-i-n silicon pad structures of size 6 × 6 mm2 and thickness 300 μm was developed for the rapid monitoring of carbon ion beam quality at the Temporary Radiobiology Facility at the Institute for High Energy Physics (TRBF IHEP) by measuring event-by-event energy release on passage of charged particles (ions) through it. This articles describes the detector design and the method used for identifying contaminants in the beam of carbon nuclei. The charge composition of the ion beam of the TRBF IHEP calculated using the amplitude spectra of signals from the p-i-n structures is presented.
316-319
Determination of Absorbed Doses in the Radiation Fields of a Neutron Generator
Abstract
A method for determining doses absorbed by biological objects on irradiation with neutrons from portable generators with energies of about 14.1 MeV was developed. The contributions of each of the components of the radiation field to the total dose were analyzed and introduced errors were assessed, permitting irradiation schemes to be optimized. Determination of dose from the intensity of neutron release from the target, despite a rather large introduced error, is quicker and more convenient than direct measurement with a dosimeter.
320-325
The Hub of an External Fixation Device for Early Mobilization of the Wrist in the Treatment of Distal Radial Epimetaphyseal Fractures
Abstract
A mobilization hub inserted into an external fixator was developed for the treatment of fractures of the distal epimetaphysis of the radius bone. The hub was designed in a three-dimensional solid-body modeling system. Experimental prototypes were made of ABS plastic by 3D printing. Cadaver experiments showed that with the device carrying the mobilization hub, the range of movements was not statistically significantly different from the range of passive movements in the intact joint. The X-ray-transparent material used for the hub provides unimpeded visualization of the fracture site and wrist joint. Single use of the hub is proposed, as it can be made using inexpensive plastic and 3D printing, while batch production is by pressure casting.
326-330
An Algorithm for Designing AC Generators for Inductive Powering Systems of Batteryless Implants
Abstract
An algorithm for designing AC generators based on class E amplifiers for inductive powering systems of batteryless implants was proposed. Parameters of three different inductive powering systems were calculated using the suggested algorithm. Each system used a pair of symmetric antennas with inductances of 3.4, 7.29, and 12.27 μH, respectively. The energy transfer efficiency and the output power of the inductive powering system based on class E amplifier were calculated as functions of the axial distance between the transmitter and the receiver for each of the three antenna pairs. The efficiencies of the systems built around antennas with inductances of 3.4 and 7.29 μH were found to be higher than 90% for axial distances in the range from 10 to 25 mm. It was found that the class E amplifier should be tuned at the minimum rather than the medium distance between the antennas.
331-334
Simulation of a Fiber Optic Flow Sensor for Measuring the Rate and Parameters of Fluid Flows in Astronaut Life Support Systems
Abstract
The design of a simplified sensing element for the fiber optic sensor used for measuring the rate and parameters of fluid flows is presented together with the diagram of forces acting in the sensing element node. A control flow diagram of the algorithm for fiber optic sensor calculation is suggested. A technique for simulation and calculation of the design and process parameters of the fiber optic sensor is developed.
335-339
340-343
Myographic Interference Filtering from ECG Signals Using Multiresolution Wavelet Transform
Abstract
Use of the multiresolution wavelet transform for the processing of ECG signals corrupted by myographic interference is considered. The influence of wavelet transform parameters on the ECG distortion level after processing is studied. The optimal parameters of the multiresolution wavelet transform are determined using criteria for minimizing distortions of processed ECG signals as compared to a model ECG signal free from interference.
344-347
Use of Neural Network-Based Deep Learning Techniques for the Diagnostics of Skin Diseases
Abstract
Melanoma is one of the most dangerous types of cancer. The accuracy of visual diagnosis of melanoma directly depends on the experience and specialty of the physician. Current development of image processing and machine learning technologies allows systems based on artificial neural convolutional networks to be created, these being better than humans in object classification tasks, including the diagnostics of malignant skin neoplasms. Presented here is an algorithm for the early diagnostics of melanoma based on artificial deep convolutional neural networks. This algorithm can discriminate benign and malignant skin tumors with an accuracy of at least 91% by examination of dermatoscopy images.
348-352
A Remote System for the Diagnosis and Emergency Care of Epileptic Seizures
Abstract
Challenges in the development of a system for the remote diagnosis of epileptic seizures occurring outside medical institutions are discussed, as are electrical stimulation of the vagus nerve to terminate epileptic seizures, automatic formation of a database of measures of epileptic seizures from long-term observations of patients, and production of a data source for physicians for planning therapeutic measures.
353-356
A History of the Discovery of the Hoorweg–Weiss–Lapicque Law
Abstract
First quantitative studies of the effect of electricity on excitable biological tissues forming the basis of the Hoorweg–Weiss–Lapicque law are described. The contribution of each researcher to the discovery is delineated and the practical significance of the Hoorweg–Weiss–Lapicque law is explained.
357-360
A Mobile Medical Thermostatic Unit Based on the Ranque–Hilsch Vortex Effect
Abstract
The paper describes the possibility of application of the vortex effect in a mobile thermostatic unit. The structural diagram of the unit and the results of tests are presented. It is shown that the technological efficiency of the Ranque–Hilsch vortex tube used in the unit can be increased by forced cooling of the tube housing or solely its hot flow outlet.
361-364