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Vol 49, No 5 (2016)
- Year: 2016
- Articles: 16
- URL: https://journals.rcsi.science/0006-3398/issue/view/14559
Theory and Design
Xenopericardial Graft Selection for Valve Apparatus of Transcatheter Heart Valve Bioprosthesis
Abstract
Samples of commercial and noncommercial xenopericardial grafts of different origin and processing are analyzed. A full-scale test of uniaxial stretching of the material was used to evaluate the features of physical and mechanical properties of the samples, and a computer finite element method simulation was used to evaluate the degree of the object compression. The results were analyzed in terms of the capacity of selected pericardial grafts to serve as a valve apparatus of a transcatheter heart valve prosthesis.
253-257
Article
Prospects for Development of Technologies for Complete Replacement of Heart Function by Mechanical Circulatory Support Systems
Abstract
The main trends in development of mechanical circulatory support systems for total heart replacement that overcome fundamental flaws of a pulsating artificial heart are described. These trends are either technological improvements of the pulsating artificial heart concept or changes in the classical concepts of the artificial heart and the corresponding structural changes. In conclusion, we present the concept of a non-pulsating total artificial heart based on two rotary pumps that is being developed at the Department of Biomedical Systems of the National Research University MIET.
258-262
Forecasting and Diagnosing Cardiovascular Disease Based on Inverse Fuzzy Models
Abstract
Advance formalization of a generalized fuzzy-logic mathematical model for forecasting and diagnosing cardiovascular complications is described. The model improves time of decision-making of anesthetist regarding the causes of complications and optimizes the perioperative period by prenosological prevention of occurring precursors of complications, reducing their total number and severity of clinical manifestations.
263-267
Flicker Noise Spectroscopy of Electrocardiographic Signals
Abstract
Application of flicker noise spectroscopy in diagnosing the functional state of the cardiovascular system to obtain distinctive features for normal state and a series of catastrophic arrhythmias is discussed. Power spectra are assessed for singular and regular ECG signal components, from which the informative features are extracted.
268-273
Reduction of Ring Artifacts in Computer Tomography
Abstract
Artifacts in projection data and images obtained by medical X-ray computer tomography were analyzed. A general-purpose tomographic image reconstruction unit was used to clarify and elaborate the artifact simulation mechanism. It allows corrupted data to be input at different stages of the image reconstruction procedure. Introduction of these data leads to occurrence of image artifacts. The artifact simulation was used to develop filtering procedures for reduction of artifacts and evaluate the filter effectiveness. An effective method for reduction of artifacts in tomographic images based on projection data filtering was found.
274-277
A Method for Acoustic Impedance Spectroscopy of the Respiratory Tract
Abstract
An original method of acoustic impedance spectroscopy of the respiratory tract in the frequency range from 4 to 100 Hz based on recording and processing of reflected polyharmonic “beep” sounds is described. The sounds are recorded using two measuring microphones. The facilities necessary for conducting the proposed method in pulmonology practice are described.
278-282
Universal Tonometer-Pulsimeter
Abstract
A compact multi-cuff device combining properties of a tonometer, pulse wave analyzer, electrocardiograph, apexcardiograph, and electronic phonendoscope is described. The device has a reference-command unit with a compressor and a monitor, supplemented with pulse wave sensors and an original phonendoscope built using fiber optics. There are also clip-electrodes for single-lead ECG recording. The sensors are connected to the device via wireless communication, providing maximum comfort for the physician.
283-287
Development of New Sensitive Broadband Elements of Sensors Based on Carbon Nanotubes
Abstract
A new type of sensitive elements based on carbon nanotubes (SECNT) was developed for photoelectric detectors of optical radiation. The optical parameters of the SECNT were tested. The working wavelength range was found to be 500-8000 nm. The maximum photosensitivity of the SECNT reached 0.7 mA/W in the near-IR range of the spectrum. The time resolution of the sensitive element was no worse than 30 μsec.
288-291
Method for Contactless Measurement of Gait Parameters
Abstract
A contactless method for measurement of gait parameters in patients walking on a moving track is described. The patterns of flexion/extension movement of knee joints were obtained by processing of videos of 16 walking volunteers. The measured patterns were compared with theoretical models described in the medical literature.
292-294
Fluid Flow Measurement in Astronauts’ Life Support Systems
Abstract
A method and a device for simulation and measurement of fluid flow parameters (volume, velocity, flow rate) are suggested. Measurement of this set of parameters is necessary for testing, optical alignment, and adjustment of the optical system of fiber-optic flow sensors used in astronauts’ life support systems.
295-299
Combined Nanostructured Magnetic Field Sensor
Abstract
A combined magnetic field sensor is described. The sensor consists of a magnetically sensitive element based on giant magnetoresistance structure and a superconducting film magnetic field concentrator. Fragmentation (nanostructuring to a branch width of 20-350 nm) of an active strip (narrow part) of the magnetic field concentrator in numerous branches and slits and modeling of their sizes (nanosizes) and locations allow the concentration coefficient and sensor efficiency to be increased by 1-2 orders of magnitude (resolution ≤ 10 pT). The efficiency of the magnetic field concentrator can be further increased if low-temperature superconductor films are used instead of high-temperature superconductor. The parameters of the suggested sensor and SQUIDs are compared.
300-303
Study of Properties of Silver-Substituted Hydroxyapatite and Biocomposite Nanostructured Coatings Based on It
Abstract
The goal of this work was to describe a method for the synthesis of silver-substituted hydroxyapatite powder. The technology and modes of plasma spraying of silver-substituted hydroxyapatite coatings are also described. Studies of the morphological and physicochemical parameters of the silver-substituted hydroxyapatite coatings using X-ray fluorescence analysis, infrared spectroscopy, transmission electron microscopy, optical microscopy, scanning electron microscopy, etc. are also discussed.
304-307
Mechanical Properties of Bulk Nanocomposite Biomaterial
Abstract
The mechanical properties of bulk nanocomposite (BNC) material prepared from an aqueous dispersion of bovine serum albumin (25 wt. %) and carbon nanotubes (~0.4 wt. %) under laser radiation were studied. The following parameters were varied during the tests: radiation power and duration, nanotube type and concentration, drying time and temperature. The BNC material has density 1200-1250 kg/m3, tensile strength σ ~35 MPa, and hardness by Vickers scale (HV) ~350 MPa, which is four to five times higher than that of dried albumin. The specific hardness 0.28 MPa/(kg/m3) and strength 0.026 MPa/(kg/m3) of the nanomaterial match those of human porous bone tissue. A mechanism for hardening the nanomaterial by forming a bulk nanocomposite framework of nanotubes was suggested.
308-311
Information System for Patients with Promyelocytic Leukemia
Abstract
An information system for patients with acute promyelocytic leukemia (APL) and the creation of a website for doctor–patient communication based on this system for ensuring decent quality of life (QL) of patients with hematologic malignancies are described. On the basis of a mathematical model available only to the doctor, a forecast of the disease progression is made, which during a remission of the patient supports the physician’s decision-making.
312-317
318-321
Mathematical Model of a Biotechnical System for Extrarenal Blood Purification Using a Portable Artificial Kidney Apparatus
Abstract
Mathematical modeling of mass transfer and metabolite removal using a biotechnical system for blood dialysis in patients with chronic kidney failure is considered. The system is based on a portable artificial kidney apparatus providing peritoneal dialysis with recirculation of the dialysis solution through the regeneration unit.
322-326