In-vitro experimental analysis of magnetic fluid hyperthermia in soft tissue with artificial blood perfusion

Mohammad Mahdi Attar,Farzan Barati,Gita Rezaei,Behroz Adelinia 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.1

Magnetic fluid exposed to an alternating magnetic field generates heat that it can be used for treatment and removal of cancerous tissue. The aim of this study is to investigate the thermal behavior of kidney tissue in magnetic fluid hyperthermia. Considering the fact that doing experiments on live tissue have some limitations, a new method is provided to test on dead tissue. In this study, an artificial circulation of the current vessels of kidney is used to make closer the behavior of dead tissue to live ones. The superparamagnetic nanoparticles with an average diameter of 20 nm have been used to heat tissue and an overview of the hardware devices needed to generate a magnetic field and to record temperature has been mentioned. Finally, the heating process has been simulated by the finite element software of Ansys. The nanoparticles injected to the tissue have a relatively spherical distribution which inevitably increases with increasing the intensity of the magnetic field and temperature difference dose. On the other hand it was observed that the rate of blood flow plays a key role in the analysis of tissue behavior and it is able to decrease the rise in temperature at most 70 %. Based on the results, it is inferred that the circulation along magnetic field intensity and dose of nanoparticles, plays a key role in the process of heating the tissue.

Thermo-mechanical analysis of soft tissue in local hyperthermia treatment

Mohammad Mahdi Attar,Mohammad Haghpanahi,Hossein Shahverdi,Ali Imam 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.3

Magnetic fluid hyperthermia is a new subclass of hyperthermia cancer treatment that can selectively heat up a tumor without damaging the surrounding healthy tissues. Some authors studied the temperature distribution of a magnetically mediated tumor assuming a homogeneous distribution of nanoparticles inside the tumor. Viscoelastic behavior of cancerous and healthy tissues have been studied in various articles and many methods have been introduced for computation of physical-mechanical properties of the tissue considering the fact that thermo-mechanical properties of the tissue completely change when the tissue becomes cancerous. Purpose of this study is to investigate thermo-visco-elastic behavior of tumorous and healthy bovine liver tissue. Therefore, the tumor is simulated as a solid sphere having radius denoted as r along with the surrounding healthy tissue. Any discontinuity between cancerous and healthy tissues is neglected. Since the resulting constitutive equations are highly complex, the stress and displacement fields were calculated by using finite difference method. An experimental test was designed to validate numerical results. Numerical results are found to be in good agreement with experimental data and with other references on homogeneous dispersion of nanoparticles.

Failure analysis of unidirectional polymeric matrix composites with two serial pin loaded-holes

Mohammad Mahdi Attar,Farzan Barati,Mahdi Ahmadpour,Ehsan Rezapour 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.6

The objective of this study is to investigate the effects of geometrical and physical parameters on failure modes and failure loads in unidirectional polymeric matrix composites with two serial pin loaded holes, analytically and experimentally. It is assumed that all of unidirectional fibers in the laminate lie in one direction while loaded by a load p 0 at infinity, parallel to the direction of the fibers. To derive equilibrium equations based on a Shear-Lag theory, a rectangular arrangement of fibers is considered and with the proper use of boundary and boundness conditions, stress and displacement fields are computed within the laminate, along with the surrounding pinholes. Finally by using the Hashin criterion failure modes and failure loads are estimated. To validate analytical results based on shear-lag theory, an experimental program is carried out. A very good agreement is observed between two procedures. Based on results, in small sizes of two pins, the dominant failure mode is bearing and with the increasing of hole sizes, failure modes are changed to tension and shear modes.

Analysis of bioheat transfer equation for hyperthermia cancer treatment

Mohammad Mahdi Attar,Mohammad Haghpanahi,Saeid Amanpour,Mohammad Mohaqeq 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.2

Magnetic fluid hyperthermia is a new subclass of hyperthermia cancer treatment that can selectively heat up a tumor without damagingthe surrounding healthy tissues. Some authors studied the temperature distribution of a magnetically mediated tumor assuming a homogeneousdistribution of nanoparticles inside the tumor. Practically speaking, the injected nanoparticles do not usually distribute uniformlythroughout the entire tumor, thus leaving some parts of the tumor without nanoparticles. In this study, an inhomogeneous dispersion ofnanoparticles inside the tumor is assumed to investigate the tissues’ temperature profiles. The problem is solved for polar coordinate. Also in this study, the heating effect of magnetic fluid in a porcine liver tissue is experimentally examined. Numerical transient solutionsare found to be in good agreement with experimental data.

Analysis of nonlinear bioheat transfer equation in magnetic fluid hyperthermia

Zahed Zomordikhani,Mohammad Mahdi Attar,Alireza Jahangiri,Farzan Barati 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.9

The objective of this study is to examine the role of blood perfusion in magnetic fluid hyperthermia by drug delivery. Although increasing blood perfusion due to high local temperature difference refers to the intelligent response of the human body, some researchers are accustomed to employing a constant rate of blood perfusion in the bioheat transfer equation. In this study, we considered a variable volumetric rate for blood perfusion in tissue, experimentally and numerically by Galerkin method. To validate the results obtained from numerical methods, an experimental procedure proposed. Furthermore, in order to transfer magnetic fluid by drug delivery, infusion pomp by which the saline serum with nanoparticles through the vein and artery was employed to make a spherical distribution in tissue. This circulation made it possible to transfer nanoparticles to tissue without any injection. After 60 minutes and changing the dark color of the saline serum to light clear, high amount of nanoparticles (about 90 %) was transferred to the tissue. After slicing the tissue, the rather spherical distribution of nanoparticles may be illustrated. Afterward, that circulation at the rate equal to blood perfusion has been made to simulate blood perfusion in dead tissue. To measure temperature, seven Lm35 sensors have been inserted into the tissue to report temperature differences. Based on results, there was seen a significant change in hyperthermic temperature difference in comparison with results obtained from Pennes' bioheat transfer equation. Additionally, a difference of about 5-10 % was seen between numerical and experimental results.

The experimental and numerical study of the effects of welding angle on forming multilayered sheets in U-bending operations

Ali Adelkhani,Hadi Ebrahimi,Mohammad Mahdi Attar 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.1

Performed was a set of experimental tests to scrutinize the effect of the welding angle and material properties on the spring-back and the displacement as well as the amount of required load in the standard bending test according to ASTM B820-18 with some numerical simulation conducting to compare those results and calculate stress through the bending process. The applied sheets were made of Copper, Aluminum and St12, DIN1623 with a thickness of 1 mm. In this study, prepared is a welding line at three angles, 30 0 , 45 0 and 90 0 whilst two punch’s radiuses have been considered. Additionally, three orientations 0 0 , 45 0 and 90 0 have been considered to check the homogeneity of the plate. Added to this, a numerical analysis utilizing finite element methods was conducted to validate the results obtained from the experimental tests. based on results, there wasn’t seen any considerable difference (less than 10 %) in terms of un-homogeneity in results while the minimum springback pressure for the St12-Cu sheet was equal to 3.6, and measured 3.70 for St12-Al. In the numerical solution, the maximum stress for the welding angle, 30, in St12-Al sheet was 305 MPa with the springback decreasing from 0.1 to 0.5 whenever the pitch radius changing from 5 to 10 mm.

Repairing cracked aluminum plates by aluminum patch using diffusion method

Sobhan Dehghanpour,Alireza Nezamabadi,Mohammad Mahdi Attar,Farzan Barati,Mehdi Tajdari 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.10

The aim of this work is to scrutinize the importance of diffusion bonding temperature, pressure and time on the repair of a cracked aluminum plate while the maximum tensile strength under a quasi-static loading has been investigated. The diffusion method was used to connect aluminum patches to repair the central and mode I cracks in thin aluminum plates. Here, the process of repairing cracked pieces made of aluminum or aluminum alloys involved a chemical and mechanical step to remove aluminum oxide and press the patch and piece under the temperature difference at a certain time. The repaired pieces underwent a quasi-static tensile loading while the maximum tolerable amount of force was obtained in different situations. Having assigned five temperatures, 300, 400, 500, 550 and 600 ° C, as well as four test times 30, 60, 120 and 180 min and five different pressures 10, 20, 50, 80 and 110 bar, we utilized fractional factorial design approach to perform 40 tests while there was seen a 10 mm initial crack in repaired samples . Experimental results showed that the optimum connection was resulted at 550 °C and the pressure of 80 bars within 120 min where the maximum force tolerated by the repaired vs. the unrepaired piece increased by 92 %. Therefore, having weighed the repair method using the diffusion bonding, we suggest that this type of the repair method can be a proper and cheap alternative to composite and adhesive patches.