A diagnostic ultrasonic probe for use in body cavities has at its tip an ultrasonic transducer array, which has a layered structure wherein a flexible circuit board, an electric circuit, a backing material, a piezoelectric element array, an acoustic impedance matching layer and an acoustic lens are formed...http://www.google.se/patents/US7794401?utm_source=gb-gplus-sharePatent US7794401 - Ultrasonic probe for intra-cavity diagnosis and manufacturing method thereof
