A Robust and Accurate Indoor Localization Using Learning-Based Fusion of Wi-Fi RTT and RSSI.

Great attention has been paid to indoor localization due to its wide range of associated applications and services. Fingerprinting and time-based localization techniques are among the most popular approaches in the field due to their promising performance. However, fingerprinting techniques usually suffer from signal fluctuations and interference, which yields unstable localization performance. On the other hand, the accuracy of time-based techniques is highly affected by multipath propagation errors and non-line-of-sight transmissions. To combat these challenges, this paper presents a hybrid deep-learning-based indoor localization system called RRLoc which fuses fingerprinting and time-based techniques with a view of combining their advantages. RRLoc leverages a novel approach for fusing received signal strength indication (RSSI) and round-trip time (RTT) measurements and extracting high-level features using deep canonical correlation analysis. The extracted features are then used in training a localization model for facilitating the location estimation process. Different modules are incorporated to improve the deep model's generalization against overtraining and noise. The experimental results obtained at two different indoor environments show that RRLoc improves localization accuracy by at least 267% and 496% compared to the state-of-the-art fingerprinting and ranging-based-multilateration techniques, respectively.

Unleashing an Underlying Serious Cardiac Arrhythmia: A Case of Coronary Vasospasm With Atypical Presentation.

This case report highlights the atypical presentation of coronary artery vasospasm in a 59-year-old patient presenting with syncope due to ventricular arrhythmia. Despite initially elevated troponin levels and non-significant lesions observed during left heart catheterization, the patient experienced recurrent chest pain and dizziness, prompting further evaluation. Ultimately, coronary vasospasm was identified as the likely differential diagnosis, supported by various diagnostic modalities including electrocardiogram, Zio patch monitoring, transthoracic echocardiogram, cardiac MRI, and CT angiography. Management involved the initiation of calcium channel blocker therapy, leading to a non-eventful follow-up in the cardiology clinic.

Thromboendarterectomy in a patient with Systemic Lupus and antiphospholipid Syndrome, lessons learned from a complex disease interaction.

Systemic lupus erythematosus (SLE) is the prototypic multisystem autoimmune disorder with a broad spectrum of clinical presentations encompassing almost all organs and tissues1. Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the occurrence of venous and/or arterial thrombosis and pregnancy morbidity in the presence of pathogenic autoantibodies known as antiphospholipid antibodies (aPL)2. Chronic thromboembolism is one of the well-known established pathogenesis of pulmonary hypertension, known as chronic thromboembolic pulmonary hypertension (CTEPH)3. APS may be also associated with other diseases, mainly systemic lupus erythematosus (SLE). The presence of secondary APS in SLE patients further aggravate the condition due to recurrent venous thromboembolic showers to the pulmonary vasculature. Pulmonary endarterectomy (PEA) is the treatment of choice for CTEPH with lifelong anticoagulation4. We herein report a rare cause of CTEPH in a 42-year-old Egyptian man who presented with dyspnea WHO-FC III. The patient was diagnosed as a case of CTEPH due to secondary APS. He underwent PEA and was discharged on lifelong anticoagulation. Clinical follow-ups thereafter showed improvement of functional capacity and pulmonary artery pressures. In conclusion, management of such cases was combination of standard treatment of CTEPH, in addition to specific management of secondary APS to avoid recurrence of the disease.