A NEW LASER-ULTRASOUND TRANSDUCER FOR MEDICAL APPLICATIONS

A new type of probe is presented, which combines an ultrasound receive r constructed from piezoelectric polymer materials with a coaxial opti cal fibre for laser-induced ultrasound. The initial application of thi s probe, which may be further miniaturized, is in intra-arterial imagi ng and therapy. Overall diameters of the prototype probes presently ra nge from 2.5 mm to 10.0 mm. Pulsed laser beams are introduced through the optical fibre to form a photoacoustic source within the material u nder investigation. Ultrasonic waves are induced in the material due t o the photo-acoustic effect and received on return by a forward-lookin g piezoelectric polymer transducer. In principle, other high-power las er beams can also be introduced through the same optical fibre for the rapeutic use. Initial development and characterization of this combine d probe is reported in this paper, together with some results.