title: The construction and assessment of lenses for local treatment of malignant tumours by ultrasound.
abstract: A simple method to build ultrasound lenses from araldite has been developed. The focussing properties of these lenses as a function of sonic frequency and lens diameter were studied using a computer model. The optimum frequency and diameter of these lens were found to be around 1 MHz and between 40 and 60 mm respectively, for deep tissue heating. The stability of the power output as well as the temperature distributions produced in vitro and in vivo have also been studied. It appears to be possible to produce larger temperature elevations near the acoustical focus than near the skin surface in vivo. Therefore the lenses seem to be suitable for local cancer treatment.
mesh_terms: D000818:Animals; D003201:Computers; D004853:Epoxy Resins; D007909:Lenses; D009369:Neoplasms / Q000628:therapy*; D010796:Phthalic Anhydrides; D013552:Swine; D014464:Ultrasonic Therapy / Q000295:instrumentation*
chemical_list: D004853:Epoxy Resins; D010796:Phthalic Anhydrides; C005752:araldite