title: Microwave ablation of ex vivo bovine tissues using a dual slot antenna with a floating metallic sleeve.
abstract: To study the efficiency of a dual slot antenna with a floating metallic sleeve on the ablation of different ex vivo bovine tissues.
  
  
  
  COMSOL Multiphysics® version 4.4 (Stockholm, Sweden), which is based on finite element methods (FEM), was used to design and simulate monopole and dual slot with sleeve antennas. Power, specific absorption rate (SAR), temperature and necrosis distributions in the selected tissues were determined using these antennas. Monopole and dual slot with sleeve antennas were designed, simulated, constructed and applied in this study based on a semi-rigid coaxial cable. Ex vivo experiments were performed on liver, lung, muscle and heart of bovine obtained from a public animal slaughter house. The microwave energy was delivered using a 2.45 GHz solid-state microwave generator at 40 W for 3, 5 and 10 min. Aspect ratio, ablation length and ablation diameter were also determined on ablated tissues and compared with simulated results. Student's t-test was used to compare the statistically significant difference between the performance of the two antennas.
  
  
  
  The dual slot antenna with sleeve produces localised microwave energy better than the monopole antenna in all ablated tissues using simulation and experimental validation methods. There were significant differences in ablation diameter and aspect ratio between the sleeve antenna and monopole antenna. Additionally, there were no significant differences between the simulation and experimental results.
  
  
  
  This study demonstrated that the dual slot antenna with sleeve produced larger ablation zones and higher sphericity index in ex vivo bovine tissues with minimal backward heating when compared with the monopole antenna.
authors.affiliation: a Radiation Biology and Radiotherapy , College of Medicine, University of Lagos , Lagos , Nigeria.
authors.forename: Ayo Zaccheaus
authors.initials: AZ
authors.lastname: Ibitoye
authors.affiliation: b Biomedical Engineering , College of Medicine, University of Lagos , Lagos , Nigeria.
authors.forename: Ephraim Okeke
authors.initials: EO
authors.lastname: Nwoye
authors.affiliation: a Radiation Biology and Radiotherapy , College of Medicine, University of Lagos , Lagos , Nigeria.
authors.forename: Adebayo Moses
authors.initials: AM
authors.lastname: Aweda
authors.affiliation: c Anatomy , College of Medicine, University of Lagos , Lagos , Nigeria.
authors.forename: Ademola A
authors.initials: AA
authors.lastname: Oremosu
authors.affiliation: d Anatomic and Molecular Pathology , College of Medicine, University of Lagos , Lagos , Nigeria.
authors.forename: Chidozie Charles
authors.initials: CC
authors.lastname: Anunobi
authors.affiliation: e Anaesthesia , College of Medicine, University of Lagos , Lagos , Nigeria.
authors.forename: Nurudeen Olanrewaju
authors.initials: NO
authors.lastname: Akanmu
mesh_terms: D055011:Ablation Techniques / Q000295:instrumentation*; D000818:Animals; D002417:Cattle; D004867:Equipment Design; D006321:Heart; D008099:Liver / Q000601:surgery; D008168:Lung / Q000601:surgery; D008872:Microwaves; D008962:Models, Theoretical; D009132:Muscles / Q000601:surgery
keywords: Different tissues; microwave ablation; monopole antenna; sleeved antenna