title: Figures of merit and their bounds in radiofrequency heating by phased arrays.
abstract: OBJECTIVE
  The problem of effective power delivery to a semi-deep target by a phased array has been addressed for application to hyperthermia treatment of some tumours in the thorax.
  
  
  METHODS
  Three efficiencies have been introduced, which estimate system ability in power transfer from generators to body, from body to tumour, and from generators to tumour. They are formulated in terms of a dissipation matrix and an interference matrix. Bounds to achievable efficiencies are obtained. Further figures of merit have also been introduced. The necessary mathematics has been developed.
  
  
  RESULTS
  A numerical analysis has been carried out for a partially interdigitated planar array of resonant dipoles. Results show how the new parameters can be exploited for optimal selection of the array's degrees of freedom.
  
  
  CONCLUSIONS
  The figures of merit and their bounds allow comparisons between RF heating devices and provide guidelines to phased array design.
authors.affiliation: Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, Rome, Italy. bardati@disp.uniroma2.it
authors.forename: Fernando
authors.initials: F
authors.lastname: Bardati
authors.forename: Piero
authors.initials: P
authors.lastname: Tognolatti
mesh_terms: D006358:Hot Temperature; D006801:Humans; D006979:Hyperthermia, Induced; D008175:Lung Neoplasms / Q000628:therapy; D008297:Male; D008962:Models, Theoretical; D011846:Radio Waves