An ultrasonic medical treatment device takes the form of an elongate probe having an elongate wave-generating concave surface with a longitudinal axis and ultrasonic electromechanical transducer elements for vibrating said concave surface to generate ultrasonic pressure waves focused along a linear locus extending parallel to said longitudinal axis. The probe may include a monolithic piezoelectric crystal element and electrode pairs provided along the unitary or monolithic element in a spaced array.
