An ultrasonic deflector for aspiration and biopsy

A new ultrasonic deflector for aspiration and biopsy is described. It is made of a Plexiglas prism (45 degrees) with an oblique hole (27 degrees). The ultrasonic beam is bent in water by about 23 degrees. A puncture needle inserted through the prism hole passes through the ultrasonic beam in water with only minimal deviation from the beam axis. A fairly strong echo from the needle tip is a useful indicator for positioning the needle for aspiration. The resolution of the ultrasonic scan is not significantly affected by the deflector. This inexpensive ultrasonic deflector is capable of performing the functions offered by the expensive ultrasonic aspiration-biopsy transducer.