When I search on DigiKey for ultrasonic transducers, all I get back is the circular transducers that are sold for the various DIY projects. i.e. the picture below:
However, the "medical" ultrasound devices have a wand, that houses an array of what seems like a linear ultrasound transducers. i.e. the picture below:
Question is, what is the correct term to name (search for) the rectangular shape vs the circular shape transducers?