RESUMO
A theoretical approach based on the electromagnetic theory of optical fibers has been applied in the analysis of the evanescent modes of a chalcogenide fiber bend used as a probe in a fiber-based spectroscopic sensor, by the example of the detection of small amounts of an antigel additive in a diesel fuel. The absorbance of the loop probe calculated for each mode was compared with the results of spectrometer-based measurements. The role of the higher-order evanescent modes of a fiber bend has been revealed. The efficiency of using a loop probe has been shown to depend on conditions of light launching into the probe.
RESUMO
The case of a 77-year-old man admitted for suspected epileptic seizure is reported. Patient history showed implantation of a single-chamber implantable cardioverter-defibrillator (ICD) after cardiac arrest in 2007 with replacement in 2012 due to battery depletion; the patient reported no previous syncope, unconsciousness or seizures. Interrogation records of the ICD showed five ventricular tachyarrhythmia episodes that corresponded to the "seizure". Further examination revealed incorrect position of the RV-lead. Diagnosis was a provoked epileptic seizure due to undersensing of ventricular tachycardia because of improper ICD lead implantation in the coronary sinus. Treatment consisted of implantation of a new device with an additional ICD lead into the right ventricle.