INTERVENTION of Bluetooth with WLAN and WIMAX

Bluetooth technology unplugs the digital peripherals and comes as cable replacement technology. IEEE 802.11 and Bluetooth are two operating in the unlicensed 2.4 GHz frequency. WiMAX is operating both licensed and unlicensed frequencies (2-11GHz). The devices equipped with IEEE 802.11 and Bluetooth are mobiles, laptops, watches and many more and in future with WiMAX. Result is the number of co-located devices may cause interference issues in the 2.4 GHz radio frequency spectrum. Bluetooth supports both voice (SCO) and data (ACL) packets. In ACL, there is retransmission of packet if it is lost while transmitting but in SCO there is no retransmission of packet. So, retransmission is big issue in Bluetooth. In this thesis, these interference issues are investigated and implement a new Bluetooth voice packet named synchronous connection-oriented with Repeated Transmission (SCORT) with WLAN interference and WiMAX interference to study the improvement in performance by using MATLAB Simulink. SCORT technique also helps in reducing co-existing interference by using HV3 type of packet in voice signal. By this technique BER does not effect at all and very minimal delay comes due to retransmission

Modelling of a High Temperature Solid Oxide Fuel Cell

Solid oxide fuel cell (SOFC) has been considered as one of the most efficient power generation devices for the coming decades. There are various physical phenomena appearing in SOFC in multi-length and -time scales, such as multi-component gas-phase species/charge flow, thermal energy and mass transfer. Meanwhile, generation and consumption of gas and surface phase species together with electric current production are involved at various active sites of different components of SOFC.In this paper, a numerical study of the thermal and electrochemical performance of a single Integrated Planar Solid Oxide Fuel Cell (IP-SOFC) has been performed. The numerical modelling considers internal reforming through the methane reforming and water gas shift reactions in a Ni-YSZ anode. Next to the description of the electrochemical reactions, the methane/steam reforming and shift reactions, the heat-transfer and the mass-transfer processes have also been included in the model. Keywords: Solid oxide fuel cell (SOFC), Integrated Planar Solid Oxide Fuel Cell (IP-SOFC), internal reforming, methane reforming, water gas shift

Childhood Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common condition in childhood and can result insevere complications if left untreated. It is showing a rising trend in India. A significantassociation with obesity has been observed; however, some children with enlargedtonsils and/or adenoids may even be underweight. The patient usually presents withsnoring and other respiratory problems like mouth breathing, choking and gaspingepisodes in night. Poor school performance and neurocognitive deficits have beenreported. Pulmonary hypertension and cor pulmonale are seen in severe cases. Besidesthe history and clinical examination, for definitive diagnosis an overnightpolysomnographic evaluation is the gold standard. In all cases, the specific treatmentranges from simple lifestyle modifications and medications to surgeries likeadenotonsillectomy. Early diagnosis is vital.Key words: Childhood OSA, Obesity, adenotonsillar hypertroph

Established and Emerging Techniques of Cardiovascular Magnetic Resonance Imaging in Coronary Artery Disease

Background. In patients with coronary artery disease (CAD), multi-parametric cardiovascular magnetic resonance (CMR) provides detailed information about the myocardial tissue composition and its function. This thesis aims to investigate how myocardial tissue composition characteristics influence its function. Additionally, this thesis aims to develop methods for time-resolved, three-dimensional flow imaging in-vitro and in health. Methods. We have prospectively recruited and conducted multi-parametric CMR in 76 patients with ST-elevation myocardial infarction (STEMI), 44 patients with stable chest pain and 35 healthy volunteers. Results. Study 1 and 2 evaluated if CMR derived function parameters are associated with the presence of microvascular obstruction (MVO) or intramyocardial haemorrhage (IMH) in STEMI patients. Study 1 demonstrated the diagnostic accuracy of mitral annular plane systolic excursion (MAPSE) to detect MVO/IMH. Study 2 demonstrated that peak global longitudinal strain (GLS) is most strongly associated with MVO/IMH when compared to other myocardial deformation parameters. Study 3 demonstrated that during first-pass perfusion stress CMR, at peak hyperemic stress, GLS is reduced in the presence of a perfusion defect in patients being investigated for CAD. Study 4 demonstrated that acute ECV-maps can reliably quantify area at risk and final infarct size (at 3-month follow) in reperfused STEMI patients. Study 5 investigated 3 main acceleration methods for 4-dimensional flow (4D Flow) in phantoms and healthy volunteers. In phantoms, all 4D Flow methods underestimated peak velocity but their mean errors were within reasonable limits for clinical applications. In volunteers, 4D echo planer imaging (EPI) method had the shortest acquisition time, best agreement with 2-dimensional phase contrast, best internal consistency between mitral and aortic valve flows. Conclusions. CMR derived longitudinal functional parameters of the left ventricle are associated with pathologies predominantly in the sub-endocardium and could be used as a surrogate imaging markers. ECV-maps offer an alternative to IS quantification. 4D EPI is the most robust acceleration method for whole-heart flow assessment

May-Thurner syndrome causing venous thromboembolism in a young female with Sturge weber syndrome and connective tissue disease

May-Thurner syndrome (MTS) is a rare condition characterized by the compression of the left common iliac vein by the overlying right common iliac artery. It is a unique causal reason for development of deep venous thrombosis (DVT) and pulmonary embolism (PE). Young females developing DVT should be examined and investigated with details as triggers can include trauma, pregnancy, autoimmunity. In this case report we report a case of a young female who had Sturge Weber Syndrome, and how a left hip pain was diagnosed as DVT which led to diagnosis of an underlying MTS and autoimmune trigger for her hypercoagulable state

Lhermitte Duclos disease: a rare cerebellar lesion with characteristic neuroimaging features

Lhermitte-Duclos disease (dysplastic cerebellar gangliocytoma) is a rare disorder of uncertain pathogenesis characterized by disarrangement of the normal cerebellar laminar cytoarchitecture. A case of histopathologically confirmed Lhermitte-Duclos disease with characteristic imaging findings and successful surgical management is reported and our findings are discussed

Meningioma mimicker: non-tubercular intradural abscess

Spinal subdural abscess (SSA) is a rare disease representing a loculated infection between the dura and the arachnoid. The infection may be due to haematogenous spread, iatrogenic contamination and local infection. Patient may present with varied symptoms ranging from backache to neurological deficit. Laboratory investigations will reveal increased white blood cell count (WBC) counts, raised erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), but these are non-specific. We present a case of a patient presenting as acute onset rapidly progressing paraplegia with initial Magnetic resonance imaging suggestive of meningioma or nerve sheath tumour. The patient was taken up for emergency surgery because of rapid progression of neurological deficit and intraoperatively found to have Spinal subdural abscess at D8-D9 level. There was no evidence of any tumour and the pus that was removed revealed Coagulase negative Staph aureus. The patient subsequently was given appropriate antibiotics for four weeks and showed clinical improvement on one month follow-up

Valve in Valve: Three-Dimensional Transoesophageal Echocardiogram and Multi-Slice CT Images of Bio-Prosthetic Aortic Valve Replaced by Medtronic CoreValve.

Valve-in-valve trans-cutaneous aortic valve implantation (TAVI) is now feasible and in a recent multi-centre study showed performed with high technical success rates, acceptable post-procedural valvular function, and excellent functional improvement.1) Multi-modality cardiac imaging in such patient's is slowly becoming routine and it is becoming pivotal for physicians to recognize structural and anatomical changes present in such patients. A 70-year-old gentleman was admitted to our unit with pyrexia and suspected infective endocarditis. He had previously undergone bio-prosthetic aortic valve implantation in 2004 for aortic stenosis. When he re-presented with heart failure in 2012 due to re-stenosis of the aortic valve bio-prosthesis, he was deemed not suitable for re-do surgery because of high-risk involved. Thus, he had TAVI using Medtronic CoreValve. Three-dimensional transoesophageal echocardiogram (3D TEE) and multi-slice contrast enhanced computed tomography (CT) scan were performed to look for the source of infection. 3D TEE clearly showed the grove of CoreValve in aortic sinus and that it was well seated (Fig. 1). Position and location of the CoreValve was also confirmed on CT thorax with 3D vascular multi-slice reconstruction (Fig. 2). Two-dimensional short-axis colour Doppler views confirmed patent left main stem and location of the strut in relation to it (Fig. 3). The highlight of this peculiar case is that the CoreValve can be recognised by 3D TEE and also CT. However, it is not possible to distinguish the remnant leaflets of the previous bio-prosthesis. This is important to bear in mind when performing and reporting TEE and CT in patients with aortic valve in valve systems. To best of our knowledge, this state-of-the-art 3D-volume rendered multi-modality imaging assessment of valve in valve TAVI has not been reported previously in literature