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Search Results: 1 - 10 of 97 matches for " Muthiah Kumaraswami "
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A Bi-Polar Triple-Output Converter with Duty Cycle Estimation  [PDF]
Kumaraswami Sundararaman, Mahadevan Gopalakrishnan
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.74019
Abstract: This paper proposes a triple output converter with buck, boost and inverted outputs and controlled through duty cycle estimation. In the existing converter, to generate the negative output, the power flows from load to the supply (from the boost output to the supply) during a part of the cycle, which increases cycle time and losses, and reduces the power level. To overcome this, a modified converter with a main and an auxiliary inductance and with reduced number of switches is proposed. The converter can operate in continuous and discontinuous conduction modes and the outputs can be independently controlled. An analysis of the converter is done for both modes. A simplified control of the converter through duty cycle estimation is suggested to regulate the outputs, which does not have the constraint that the current ripple has to be small. The control works both in the continuous and discontinuous modes. The simulation results closely match with the analysis. A prototype of the converter is constructed with a Spartan FPGA system and results have been presented.
Left Atrial Myxoma—A Case Report  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.51002
Abstract: Atrial myxomas are the most common primary cardiac tumors. More than 90% are solitary. A large myxoma occupying in the left atrium producing mitral stenosis and regurgitation was demonstrated by 2D echocardiographic images in this case. It remained asymptomatic for a long period with a survival up to the age of 75 years in an elderly female.
Apical Right Ventricular Hypertrophic Cardiomyopathy—A Case Report  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.52010
Abstract: A relatively infrequent form of hypertrophic cardiomyopathy is the isolated apical variant and it is more common in oriental people, especially in the Japanese. It contributes 25% of cases of hypertrophic cardiomyopathy in Japan but only 1% to 2% in the non-Japanese population. It may occasionally present in the elderly and classically involve the apex of the left ventricle. An isolated apical right ventricular involvement had been detected in an elderly female by transthoracic two-dimensional echocardiographic imaging.
Right Atrial Myxoma—A Case Report  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.53013
Abstract: Myxomas comprise 6% to 10% of primary cardiac tumors in childhood. Less than 10% of patients with cardiac myxomas are under 15 years of age. A large myxoma occupying in the right atrium and prolapsing into the right ventricle, pulmonary artery and producing tricuspid and pulmonary valve obstructions was diagnosed by Transthoracic 2D echocardiographic imaging in a 12-year-old male child.
Left Ventricular Myxoma—A Case Report  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.53016
Abstract: Left ventricular myxomas are extremely rare and account for 2.5% of all cardiac myxoma cases. A left ventricular myxoma originating from the apical interventricular septum and projecting into the left ventricular cavity was diagnosed by Transthoracic two-dimensional echocardiographic imaging in a 29-year-old male. The presentation of myxoma with symptoms masquerading as infectious hepatitis and dilated cardiomyopathy with a measured ejection fraction of 20% has been described.
Left Ventricular “Horseshoe-Thrombus”—A Case Report  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.54026
Abstract: Thrombi represent the most frequently found intracardiac masses. Left ventricular thrombus (LVT) is an important complication in patients with ischemic heart diseases and in those with dilated cardiomyopathy and systolic heart failure. The diagnosis of left ventricular thrombus remains important since anticoagulation will reduce the risk of systemic embolization and stroke. Despite advances in other imaging modalities, echocardiography remains the most important tool for diagnosis and risk stratification in patients predisposed to develop left ventricular thrombi. Mural thrombi formed on the left ventricular endocardium and horseshoe-shaped in chronic dilated cardiomyopathy, masquerading as left ventricular endomyocardial fibrosis was diagnosed by transthoracic 2D echocardiographic imaging in a 38 years old middle aged man. Background of this case highlighted the pathophysiology, high risk echocardiographic features and the role of anticoagulant therapy in LV thrombus with dilated cardiomyopathy.
Right Ventricular Myxoma—A Case Report  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.54030
Abstract: From an epidemiologic perspective, cardiac myxomas are best divided into the following 2 categories: those that arise in isolation and those that arise in the setting of a syndrome (so called Carney Complex). The former account for about 90% - 95% of cases, while the later account for a minority of cases and those arise from the right or left ventricle constitute as 3% each. Real-time two-dimensional echocardiography has proved to be extremely useful in defining intracavitary masses. With two-dimensional echocardiography accurate visualization of the right ventricular body and outflow tract can be accomplished consistently. The acoustic nature and anterior location of the right ventricular myxomas make them appear as bright, mobile masses. The mobile nature of the tumor can easily be appreciated and its point of attachment, or stalk can be visualized accurately. Background of this case illustrates the transthoracic 2D echocardiographic pattern of right ventricular myxoma and its attachment by a pedicle to the anterior papillary muscle, masquerading as ball-valve thrombus and cardiac “stone” in tilted parasternal long axis-3 chamber views in a 15-year-old girl. Mahaim criteria to distinguish myxoma from organizing thrombus had been highlighted.
Endomyocardial Fibrosis: Echocardiographic Profile  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.55034
Abstract: Evolution of two-dimensional and color Doppler echocardiography identified the typical features of Endomyocardial Fibrosis (EMF) such as dense ventricular apical fibrosis, dysfunction of atrioventricular valve and sub-valvular apparatus and cavity dimensions. This is the tool used most for the diagnosis of EMF in areas where the disease is endemic in Africa. Today echocardiography is used as a screening tool to identify cases of EMF at the community level and it could be confirmed at the bed side. Background of these cases highlighted the echocardiographic features of EMF in different age groups and the oldest one reported at the age of 85 years in a female in advanced stage at this coastal district of Thoothukudi in India.
Right Ventricular Endomyocardial Fibrosis in Neonate—A Case Report  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.55032
Abstract: Endomyocardial fibrosis is characterized by the formation of fibrous tissue in the endocardium. Although the disease may affect both ventricles, isolated or not, the right ventricle is more frequently involved. Endocardial fibrosis may be present in the entire ventricular cavity, being usually more marked in the apical region and right ventricular inflow tract. Its etiology, however, still remains unknown. Background—Reports on endomyocardial fibrosis in pediatric patients are not common. It is more frequent from the fourth year of age on, with few reports in the first 2 years of life. This case aimed at reporting right ventricular endomyocardial fibrosis in 7 days old male neonate, in addition to discussing the etiopathogenesis and future perspective of the disease.
Quadrivalvar Rheumatic Cardiopathy in Tetralogy of Fallot in an Adult—A Case Report  [PDF]
Ramachandran Muthiah
Case Reports in Clinical Medicine (CRCM) , 2016, DOI: 10.4236/crcm.2016.56036
Abstract: Rheumatic involvement of all four heart valves is uncommon and its association with congenital heart disease is very rare. Tetralogy of Fallot is a frequent cyanotic congenital heart disease with a survival beyond middle age. Background of this case report described the rheumatic involvement of all four heart valves (quadrivalvar rheumatic cardiopathy) with stenotic lesions of semilunar valves (aortic and pulmonary valves) and regurgitant lesions of atrioventricular valves (mitral and tricuspid valves) in Tetralogy of Fallot in a 48-year old asymptomatic female, detected by transthoracic two dimensional echocardiography in Thoothukudi region of India.
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