Sökning: "radiofrequency"

Visar resultat 1 - 5 av 50 avhandlingar innehållade ordet radiofrequency.

  1. 1. Radiofrequency fields : exposure, dose and health

    Författare :Jonna Wilén; Umeå universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electromagnetic fields; SAR; Specific Absorption; subjective symptoms;

    Sammanfattning : The overall aim of this thesis is to increase our knowledge of relevant exposure parameters when discussing possible health implication from exposure to radiofrequency electromagnetic fields (RF), especially effects that might occur at non-thermal levels.In this thesis an effort is made to broaden the exposure assessment and to take the exposure time into account and combine it with the Specific Absorption Rate (SAR) and the field parameters (electric and magnetic field strength) to approach a dose concept. LÄS MER

  3. 2. Evaluation of surgical methods for sleep apnea and snoring

    Författare :Thorbjörn Holmlund; Diana Berggren; Eva Levring Jäghagen; Karl Franklin; Sören Berg; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Sleep apnea syndromes; adverse effects; mortality; radiofrequency; sham surgery; randomized controlled trial; daytime sleepiness; snoring; tonsillar hypertrophy; tonsillectomy; cytoskeleton; desmin; dystrophin; muscle fiber; palatopharyngeus; soft palate; uvula.; Oto-Rhino-Laryngology; oto-rhino-laryngologi;

    Sammanfattning : Background: Snoring and obstructive sleep apnea (OSA) are both common disorders with a number of negative health effects. The safety and efficacy of treating snoring and OSA surgically have been questioned and there has been a lack of studies in the field. LÄS MER

  4. 3. Aspects of Intraoperative Ablation for Atrial Fibrillation

    Författare :Birgitta Johansson; Göteborgs universitet; []
    Nyckelord :atrial fibrillation; intraoperative ablation; radiofrequency; cryo; epicardial; quality of life; atrial function; predictors of rhythm;

    Sammanfattning : Background: Increasing knowledge about mechanisms that trigger and maintain atrial fibrillation (AF) has influenced the possibilities for treatment and even cure of AF. The surgical Cox Maze III procedure is still the gold standard for the curative treatment of AF. LÄS MER

  5. 4. Outcomes and safety of new techniques for pulmonary vein isolation in patients with paroxysmal and persistent atrial fibrillation : A study based on randomised trials and registries

    Författare :David Mörtsell; Carina Blomström-Lundqvist; Stefan Lönnerholm; Isabel Deisenhofer; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; atrial fibrillation; antiarrhythmic drugs; ablation; cryoballoon; radiofrequency; pulmonary vein isolation; quality of life; arrhythmia monitoring; implantable cardiac monitor; atrial fibrillation burden; health economics; Cardiology; Kardiologi;

    Sammanfattning : Atrial fibrillation (AF) is a common disease with a high prevalence in the adult population. Treatment of AF encompasses antiarrhythmic drugs and catheter ablation to reduce symptoms. LÄS MER

  7. 5. Submillimeter-Wave Waveguide Frontends by Silicon-on-Insulator Micromachining

    Författare :Adrian Gomez-Torrent; Joachim Oberhammer; Umer Shah; Goutam Chattopadhyay; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antenna; orthomode transducer; switch; waveguide; radiofrequency; beamforming network; submillimeter-wave; terahertz; silicon micromachining; deep reactive ion etching; silicon on insulator; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : This thesis presents novel radiofrequency (RF) frontend components in the submillimeter-wave (sub-mmW) range implemented by silicon micromachining, or deep reactive ion etching (DRIE). DRIE is rapidly becoming a driving technology for the fabrication of waveguide components and systems when approaching the terahertz (THz) frequency range. LÄS MER