Electromagnetic acoustic pressure pulse source - has breakdown resistant insulating foils, useful in medical treatment

摘要

Electromagnetic acoustic pressure pulse source has an electrically conductive membrane (2) and an electric coil (4) which are sepd. and electrically insulated from one another by two or more insulating foils (5a, b) the total thickness of which does not (significantly) exceed the thickness of a single insulating foil which has the desired breakdown resistance and which is formed of the same material or of the material of the insulating fol with the lowest specific breakdown resistance. Pref. at least one of the foils (5a, b) is made of polyimide, PTFE or polyester terephthalate and an adhesive layer (15a, b) of acrylate phenolic resin and/or epoxy resin adhesive is provided between a foil (5a) and the coil (4) and/or between the foils (5a, b). USE/ADVANTAGE - In medicine for treatment of stones (lithotrity), tumours and bones (osteo-restoration). The design reduces the risk of voltage breakdown between the coil and membrane without significant redn. in efficiency of conversion of electrical to acoustic energy.