Saratov JOURNAL of Medical and Scientific Research

Ivanov D.V.

Saratov National Research State University n. a. N. G. Cherny-shevsky, Associate Professor of Department of Mathematical Theory of Elasticity and Biomechanics; Saratov State Medical University n. a. V. I. Razumovsky, Scientifc Research Institute of Traumatology, Orthopedics and Neurosurgery, Analyst of Department of Intellectual Property and Technology Transfer, PhD

Optimization of the process of creating models of human blood vessels

Year: 2019, volume 15 Issue: №2 Pages: 353-357
Heading: Human anatomy Article type: Original article
Authors: Dol A.V., Ivanov D.V., Fomkina O.A.
Organization: Saratov National Research University n.a. N. G. Chernyshevsky, Saratov State Medical University
Summary:

Objective: to optimize the process of biomechanical modeling of blood vessels on the example of creating models of the arterial circle of the brain. Material and Methods. Biomechanical modeling requires the creation of a patient-oriented three-dimensional solid-state geometric model of the object under study. This problem can be solved by computer data processing (CT) or magnetic resonance (MRI) tomography. A program that implements the construction of blood vessel contours on individual sections of MRI in semi-automatic mode. These contours are exported as saved curves in a specifc format to SolidWorks, where they are used to create three-dimensional models of blood vessels. The models obtained in this way take into account the personal characteristics of the structure of the vascular bed of a particular patient and can be used in the process of biomechanical modeling. Results. The results of the program implementation of the recursive frontal growth method for processing two- dimensional slices of tomograms are presented. Conclusion. The developed software allows semi- automatic loading of DICOM images and obtaining fat sections of vessels on their basis, as well as transferring them for further processing into computer-aided design systems.

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Optimization of transpedicular spondylosynthesis application for type A3 lesions of the thoracolumbar transition: clinical experimental study

Year: 2019, volume 15 Issue: №2 Pages: 275-283
Heading: Traumatology and Orthopedics Article type: Original article
Authors: Likhachev S.V., Zaretskov V.V., Arsenievich V.B., Shchanitsyn I.N., Shulga A.E., Zaretskov A.V., Ivanov D.V.
Organization: Saratov National Research University n.a. N. G. Chernyshevsky
Summary:

Objective: the optimization of transpedicular systems application for type A3 lesions of the thoracolumbar transition using computer simulation based on the fnite elements method. Material and Methods. The examination data (post-traumatic kyphotic deformation, intensity of pain syndrome, length of operation and extent of blood loss) of 81 prospec-tively enrolled male patients who in 2017–2018 had been operated for Th11-L2 vertebrae simple fractures of А3N0M1 type (AOSpine classifcation). The patients were divided into 3 groups in accordance with the type of intervention performed on them: short-segment (n=42), 8-screws polysegment (n=25) and 6-screws polysegment (n=14). Biome-chanical simulation based on the computer tomography data was performed for each variant of the metal construction arrangement. Results. In the process of biomechanical simulation with all the variants of the instrumented spine 3D- models loading 8-screws construction proved to be the most consistent one, at that the stability of polysegmental constructions exceeds that of bisegmental one by an order. The results of surgical management were evaluated in terms of up to a year following the intervention. The loss was less and the correction worked better with polysegmental fxation despite more complicated initial conditions for the correction compared to those of group 1 Conclusion. Biomechanical simulation shows prerequisites for the development of bisegmental systems instability as the equivalent stresses and peak displacements are higher compared to those of polysegmental fxation. The efciency analysis of application of various transpedicular fxations for type A3 thoracolumbar transition lesions attests to the advantage of polysegmental arrangements of transpedicular systems, at that the implantation of the 6- screws polysegmental system should be considered the frst choice on the number of indices.

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Justification of intramedullary fixation devices modification and first clinical experience of application of the SarNIITO nails for femur shaft osteosynthesis

Year: 2019, volume 15 Issue: №1 Pages: 52-57
Heading: Traumatology and Orthopedics Article type: Original article
Authors: Barabash А.Р., Norkin I.A., Barabash Yu.A., Ivanov D.V., Zuev P.P., Shpinyak S.P.
Organization:
Summary:

Objective: to estimate the changes of effective stresses (by Mises) at three types of loads (axial, lateral and twisting) for various types of intramedullary nails synthesizing modeled fractures of A1; A3; B2 types at the level of femur bone middle third. Material and Methods. To solve the preclinical tasks computer simulation of biomechanical systems bone-fixing pin and method of finite elements were employed. Results. The nails developed by SarNIITO excel ChM and Fixion rods in stress-deformed condition, fatigue strength and stability of fixation of the examined types of fractures parameters of 12- 23%. Conclusion. The mechanical characteristics of SarNIITO nails proved to be of clinical use and may be recommended for patients with femur bone diaphysis fractures.

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Computer modeling of biomechanical systems «femoral bone — endoprosthesis / transplant — tibia» in different methods of anterior cruciate ligament plastics in knee joint

Year: 2017, volume 13 Issue: №3 Pages: 764-768
Heading: Traumatology and Orthopedics Article type: Original article
Authors: Shormanov A.M., Ivanov D.V., Norkin A.l., Ulyanov V.Yu., Bakhteeva N.Kh., Klimov S.S., Chibrikova Yu.A.
Organization: Saratov State Medical University
Summary:

The aim: to specify the indices of dislocation (displacement) and effective stress in biomechanical systems «femoral bone — endoprosthesis / transplant — tibia» in different methods of anterior cruciate ligament by computer modeling of a knee joint geometrically, physically and mechanically similar to human. Material and Methods. Steady-state tasks of the stress given on a knee joint after anterior cruciate ligament plastics fulfilled by different methods were resolved numerically by the method of finite elements implemented in the system of finite element analysis. Results. Maximum dislocations comprised 3.45 mm. for the method of single-beam plastics of ACL, 0.35 mm. for two-beam plastics and 0.93 mm. for plastics with semi-tendinous and gracilis tendons. Maximum stress were 1190 MPa for single-beam plastics of ACL, 141 MPa for two-beam plastics and 150 MPa for plastics with semi-tendinous and gracilis tendons. Conclusion. Finite element modeling of different ways of ACL plastics indicates higher stability of synthetic endoprosthesis under rising stress in case of two-beam plastics and transplant of semi tendinous and gracilis tendons compared to the single-beam plastics.

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Biomechanical modelling of cerebral arteries at different variants of configuration of intracranial arteries of vertebrobasilar system

Year: 2016, volume 12 Issue: №2 Pages: 118-127
Heading: Macro- and Micromorphology Article type: Original article
Authors: Fomkina О.А., Ivanov D.V., Kirillova I.V., Nikolenko V.N.
Organization: Saratov State Medical University, Saratov state university
Summary:

The purpose is to consider the biomechanical modelling of cerebral arteries at different structural variants of intracranial arteries of vertebrobasilar system. Material and methods. By means of the system of the final and element analysis ANSYS on the basis of data on geometry, morphometricand biomechanical properties of cerebral arteries their biomechanical models have been constructed. On the received models for 9 structural variants of intracranial arteries of vertebrobasilar system, haemodynamic parameters and parameters of the intense deformed condition of walls of arteries have been analyzed. Results. The most frequent variant of a configuration of intracranial department of vertebrobasilar system is the combination of average in size of angles of connection of vertebrata and bifurcation of basilar arteries. Such option occurs in 49% of cases. More rare variant (1,5% of cases) with the narrow angles of connection of vertebrata and bifurcations of basilar arteries has been observed. The design of intracranial arteries of vertebrabasi-lar system exerts an impact on distribution of bloodflow and effective tension in a vascular wall of back brain arteries. Conclusion. According to the study it has been determined that the constructed individual biomechanical models may provide information on some parameters of haemodynamics and the intense deformed condition of a vascular wall which causes the development of atherosclerosis and intracranial aneurisms.

The possibility of different CAD systems in the construction of mathematical model of bone tissue

Year: 2013, volume 9 Issue: №3 Pages: 403-405
Heading: Stomatology Article type: Author's opinion
Authors: Ivanov D.V., Lepilin A.V., Smirnov D.A., Dol A.V.
Organization: Saratov State Medical University, Saratov state university
Summary:

Modern methods of diagnosing of maxillary bones in various clinical situations presume a method of computer tomography. In some cases, the treatment planning according to three-dimensional image cannot be performed and the question of creation of the biomechanical model study area arises. Various methods of computer-aided design and three-dimensional modeling are worth while using to achieve the realization of the task.

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Age-Specific And Sexual Variability Of Morphological And Biomechanical Parameters Of Anterior Cerebral Artery Of Adults

Year: 2009, volume 5 Issue: №4 Pages: 482-485
Heading: Macro- and Micromorphology Article type: Original article
Authors: V.N. Nikolenko, О.А. Fomkina, I.V. Kirillova, D.V. Ivanov
Organization: Saratov State Medical University, Saratov National Research University n.a. N. G. Chernyshevsky
Summary:

In the experiment on monoaxonic longitudinal distension by tensile-testing machine Tira Test 28005 (Germany) with loading unit - 100 N the general rigidity, breaking point and relative lengthening of anterior cerebral artery (АСА) of adult people have been under study. Under the microscope on transverse sections the external diameter of the artery, its wall thickness have been measured and diameter of lumen have been calculated. In total 228 АСА (132 - from corpses of men, 92-from corpses of women) have been investigated. They have been received in 16 hours after autopsy of adult people whose cause of death has not been connected with vascular cerebral pathology.
It has been revealed that right АСА is longer and narrower than left one. ACA's wall length and thickness predominate in men in comparison with women in average of 5,4 - 13,0%. With years АСА lengthens, its external diameter increases. Biomechanical parameters of ACA's wall do not have any authentic sexual differences, they don't depend on the side of the arterial ring. With years the rigidity of АСА decreases, especially in middle age. In old age its general rigidity increases. It is connected with the increase of ACA's wall thickness. The ability of АСА to lengthening doesn't depend upon age. Experimental findings may be used as criteria of age standard of morphological and biomechanical parameters of АСА

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