Transducer beam pattern test object.

A new test object has been developed that generates images of transducer beam patterns on B-mode hardcopy. The extent and depth of the transducer focal zone are measured from these images. The predictions made from test object images were verified in the clinical images obtained from two 3.5-MHz focused transducers. Using the test object images, we have found that we can make a more rational selection of transducer for each clinical situation.