Abstract: An ultrasonic wave transducer is formed from a body of piezoelectric material having nonuniform thickness. Each location on the transducer is resonant at a different frequency according to the thickness at that point. By changing the frequency of the applied excitation signal, the origin and direction of the radiation can be altered.

Abstract: A transducer assembly is provided for moving a transducer into operative contact with a human eye. The assembly comprises a transducer holder that receives a transducer therein. A slide supports the transducer holder for rearward movement from a home position. A spring normally biases the transducer holder to the home position. Thus, as the assembly is moved toward the eye and the transducer engages the eye, the slide moves rearwardly against the spring bias to maintain the transducer against the eye of the patient. In order to prevent undue force on the eye, a release device is provided between the transducer holder and the transducer and is responsive to a preselected value of force for releasing the transducer from the transducer holder.