Evaluation of an aperiodic phased array for prostate thermal therapies

A 57 element aperiodic linear phased array was designed and constructed to investigate the feasibility of using transrectal ultrasound for thermal therapeutic treatment of diseases of the prostate. A method of reducing grating lobe levels by using optimized random distributions of unequally sized elements was used, which made it feasible to use larger elements and hence fewer elements and amplifier channels, while still achieving acceptable power field patterns. The heating capabilities of this array were investigated using an ex vivo perfused kidney for hyperthermia and fresh bovine liver for thermal surgery. The experiments demonstrated that the aperiodic array was capable of generating and controlling adequate power for the purposes of hyperthermia and thermal surgery.