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Krishnan, J.
- Modelling of Four Compartment Model of Cardiovascular System using Simulation
Authors
1 Department of Electronics and Instrumentation Engineering, Annamalai University, Annamalai Nagar, Tamilnadu, IN
2 Department of Electronics and Instrumentation Engineering, Annamalai University, Annamalai Nagar, Tamilnadu, IN
Source
Biometrics and Bioinformatics, Vol 5, No 1 (2013), Pagination: 1-6Abstract
Cardiovascular system is one of the main systems of our human body. There are several cardiovascular problems that have a significant effect on health expenditures in industrialized countries; moreover it reduces patient’s quality of life. In this point of view, current research focuses on detailed modeling of the cardiovascular system. Thus, this paper aims to present a model of the heart enhanced with a widespread model of the cardiovascular system. A mathematical description of this system can provide more insight. So computer-based simulation of the cardiovascular system is analyzed and simulation is done using matlab/simulink software. Instead of a hydraulic model, an inexpensive, compact and simple electrical circuit consisting of resistances, capacitances, inductances and diodes has been constructed, using parametric values that are transformed from hydraulic models. In order to obtain the more accurate model than those used in prior investigations in the literature, a baroreceptor model has been introduced. The model outputs are flow/pressure waveforms, which exhibit a similarity with physiological curves. The elastance was modeled in the form of sine wave which has a parameter H. The parameter H present in the sine wave was altered, corresponding arterial pressure is obtained. Optimal parameter H input to sin wave is found.Keywords
Cardiovascular System, Heart, Modelling, Pressure.- Vertebral Fracture Assessment and Classification using Imaging Techniques – An Overview
Authors
1 Department of Electrical Engineering in Annamalai University, IN
2 Department of Electronics and Instrumentation Engineering in Annamalai University, IN
Source
Biometrics and Bioinformatics, Vol 5, No 1 (2013), Pagination: 7-13Abstract
Vertebral fracture is the most common type of fragility fracture, even these are not clinically apparent. It is now recognized that they are associated with increased risk of future fracture, increased morbidity, and increased mortality. Vertebral fractures are common osteoporotic fractures, but current quantitative detection methods (morphometry) lack specificity. Vertebral fracture assessment is a method for imaging the spine by dual-energy X-ray absorptiometry to diagnose vertebral fractures. Vertebral fracture assessment exposes the patient to less radiation than conventional spine radiographs, with lower cost and greater convenience. Vertebrae were first classified by radiologists for vertebral fractures and differentiate them from other causes of vertebral deformities. The mild deformities are diagnosed. Fractured vertebrae were graded. AAM was used to provide a semi-automatic segmentation. The resulting segmentations were used for the classification algorithm. Classifier‟s measure of the fracture likelihood estimate was found. Statistical comparisons were done between the classifiers.Keywords
Active Appearance Model (AAM), Bone Mineral Density, Computer-Assisted Diagnosis, Dual-Energy X-Ray Absorptiometry (DXA), Osteoporosis, Semi Quantitative Assessment, Vertebral Fracture Assessment (VFA).- Effects of Gap Junction Conductance in Synchronizing Cardiac Oscillators
Authors
1 Electronics and Instrumentation Engineering Department, Annamalai University, Annamalai Nagar, Tamilnadu, 608002, IN
Source
Biometrics and Bioinformatics, Vol 4, No 10 (2012), Pagination: 454-458Abstract
The auto-rhythmic cells in the Rabbit heart beat at a wide range of frequencies (330-80 beats per minute) in culture, but in the whole heart they beat at a common frequency set by the normal sinus rhythm. For such a varied range of intrinsic frequencies in a large network of oscillators synchronization becomes much more difficult. Keeping this in mind, an attempt has been made with the help of electro physiology model of cardiac pacemaker cells to analyze the synchronization issue in the syncytium of the cardiac system. A single cell model of a rabbit sinoatrial node was simulated using Matlab package and it was found that the simulated results matched with the experimental findings. Being a sinoatrial nodal cell there exist a parameter for varying the frequency of the generated action potential. After a thorough study of the single cell model, cells were coupled via a coupling element that resembles Gap Junction conductance in real electrophysiology, thus a pair of cell is developed. The intrinsic frequencies of the cells were varied to all possible extents and it was observed that the cells were oscillating in a new frequency and thereby failed to synchronize. The significant role of gap junctions in establishing synchronization was carried out. These investigations emphasized the role of gap junction conductance in their role in synchronization.Keywords
Action Potential, Cardiac Pacemaker Cell, Gap Junction Conductance, Intrinsic Frequency, Sinoatrial Node.- Wear Behavior of Al-Steel Solid State Coating Produced by Friction Surfacing
Authors
1 Mechanical Engineering Department, School of Technology, Pandit Deendayal Petroleum University, Gandhinagar, IN
2 The M.S.University of Baroda, Vadodara, IN
Source
Indian Welding Journal, Vol 49, No 4 (2016), Pagination: 45-45Abstract
Normally steels are coated with zinc or aluminium to protect them against atmospheric corrosion. Aluminium is being use as anode for the protection of ships, especially of war ships,marine vessels which are exposed to sea water. Aluminium deposition on mild steel by fusion welding is not feasible as it chemically reacts to form iron aluminide, and Fe and Al are immiscible. Hence, a solid state deposition is a possible option.
During Friction surfacing process rubbing of the rotating consumable rod against subtract, is pressed against the substrate under an applied axial load. Friction between rod and substrate generates a viscoplastic boundary layer at the rod tip. Temperature and pressure conditions lead to an inter diffusion at the interface resulting metallic bond between the plasticized material and the substrate.
In the present investigation, aluminum alloy coating on steel substrate developed by friction surfacing. AA6351 T6 used as a consumable material and SA516 Gr70 steel used as a substrate material. Al rod of the 22mm in diameter was selected for the deposition on 6mm thick steel plate using experimentally optimized variables. At constant FS variables multi-layer samples generated (single layer, double layer and triple layer). Afterwards samples subjected to metallurgical investigation includes microstructure, micro hardness and Pin on disc wear test at 60N load. Wear rate of multilayer specimens compared with original rod as well as with deformed rod. Wear rate of multilayer specimens is lower than that of original rod. Micro handedness value is higher at the interfaces, additionally mechanical interlocking observed at the interface.
Keywords
Friction Surfacing, Wear Behaviour of FS Deposit, Multi-Layer.- Materials of Construction for Petrochemical Industries
Authors
1 CWS. BARC, Mumbai, IN
Source
Indian Welding Journal, Vol 31, No 3 (1998), Pagination: 17-24Abstract
Petroleum is a heavy, liquid, flammable oil stored under the surface of the earth and originally formed as the by-product of the action of bacteria on marine plants and animals.- Underwater welding- its mechanism, challenges, risks and recent advancements
Authors
1 Department of Metallurical and Materials Engineering The M. S. University of Baroda, Vadodara - 390001, IN
2 Department of Metallurical and Materials Engineering The M. S. University of Baroda, Vadodara - 390001, IN
Source
Indian Welding Journal, Vol 56, No 2 (2023), Pagination: 47-52Abstract
Underwater weiding invoives a high degree of technicai compiexity. It is basicaiiy appiied in ship buiiding and maintenance, waterway structures, submarines, subsea pipelines, offshore oii rigs and nuciear reactors etc. High quaiity standards are required for underwater weiding systems and personnei. Undenwater weiding profession is attracting much more than other professions since it is more chaiienging and highiy paid. In view of this fact, an attempt has been made to briefly discuss its mechanism, chalienges, risi<s and recent advancements.Keywords
Underwater weiding, Mechanism, Challenges, Risks, AdvancementsReferences
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