Sentence:  By submerging the patient in a <WSD>tub</WSD> and rotating the transducer while the scanning goes on , they have been able to get cross-section views of the neck , as shown in Fig. 7 , as well as many other hitherto impossible insights . 
Meaning of the word marked with <WSD> tags:  a relatively large open container that you fill with water and use to wash the body