Air-coupled and water immersion sectorized array transducers for industrial and medical endoscopy

Inspection of large or small pipes is commonly found in many different ultrasonic industrial applications. Pigs are commonly used for large pipes and inspection under working conditions. Small pipes are inspected from inside by using endoscopes, but the distance to be inspected can be limited by the pipe diameter, geometry and section variations. In medical applications, ultrasonic endoscopy are used as diagnosis tool for arteries (IVUS) and the gastrointestinal tract. Flat transducers with conical reflectors have already been proposed for industrial and robotics applications (echolocation) but the main drawback, in the case of endoscopic applications, is the need to keep the transducer aligned with the pipe axis.