Sökning: "Conduction Disturbances"

Visar resultat 1 - 5 av 19 avhandlingar innehållade orden Conduction Disturbances.

1. 1. Conduction Disturbances in Patients with Atrial Fibrillation

   Författare :Eva Hertervig; Kardiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Kardiovaskulära systemet; Cardiovascular system; Pulmonary Vein Potentials; Atrial Fibrillation; Conduction Disturbances;

   Sammanfattning : Background: The electrophysiological mechanisms underlying atrial fibrillation (AF) are incompletely understood. Experimental studies have shown that remodelling of the atrial myocardium is linked to the occurrence and perpetuation of AF. LÄS MER

3. 2. Modelling and Interference Analysis of AC-DC Converters for Immunity to Voltage Disturbances up to 150 kHz

   Författare :Selcuk Sakar; Sarah Rönnberg; Math Bollen; Sjef Cobben; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AC-DC power converters; electromagnetic compatibility EMC ; high frequency disturbances; supraharmonics; switching converters; interharmonics; conducted disturbances; Electric Power Engineering; Elkraftteknik;

   Sammanfattning : The function of electrical and electronic equipment is challenged by the high frequency emission originated from the more use of switching-based power electronic equipment and Power line communication (PLC) signaling. Investigations have shown that interferences occur in the frequency range between 2 kHz and 150 kHz, e.g. LÄS MER

4. 3. The Role of Impaired Interatrial Conduction in Paroxysmal Atrial Fibrillation

   Författare :Pyotr Platonov; Kardiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; electrophysiology; Cardiovascular system; anatomy; interatrial conduction; lone atrial fibrillation; Kardiovaskulära systemet;

   Sammanfattning : The aim of this thesis was to evaluate the role of interatrial conduction defects in the genesis of lone paroxysmal atrial fibrillation (AF) using combined approach of non-invasive signal-averaged P-wave ECG, invasive electrophysiological (EP) studies, anatomical studies and animal experiments. Non-filtered signal-averaged P-wave ECG revealed irregularities in orthogonal P-wave morphology and the presence of double-peaked configurations of P-wave spatial magnitude in patients with lone paroxysmal AF compared with healthy individuals (I), suggesting the presence of interatrial conduction delays localised in the posterior-inferior interatrial route. LÄS MER

5. 4. Observations of Interatrial Conduction in Healthy Individuals Using Signal-averaged P-wave ECG: A Clinical Perspective

   Författare :Rasmus Havmöller; Kardiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; signal-averaged; interatrial conduction; orthogonal; P-wave; ECG; healthy;

   Sammanfattning : Disturbances of interatrial conduction are linked to supraventricular arrhythmias. Previous studies have shown that these disturbances can be detected non-invasively as distinctive appearances of the orthogonal P wave using signal-averaged P-wave analysis (PSAECG). LÄS MER

7. 5. Counteracting Acoustic Disturbances in Human Speech Communication

   Författare :Nils Westerlund; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speech Enhancement; Noise Reduction; Hearing Aids; Adaptive Feedback Control; Ear-Mic; Active Noise Control;

   Sammanfattning : A signal can be said to be any information bearing unit or action carrying a message from a sender to a receiver. This definition covers a vast number of human and non-human actions, ranging from flirtation to satellite communication. This thesis deals with increasing the quality of one of the most ubiquitous human-to-human signals: Speech. LÄS MER