Design of a multi-layer transducer for acoustic bladder volume assessment

Catheterization remains the golden standard for bladder volume assessment, but it is invasive and introduces the risk of infection and trauma. Therefore, noninvasive bladder volume measurement methods are of high interest. In a preceding study, we proposed a new technique to measure bladder volume based on nonlinear ultrasound wave distortion. A dedicated multi-layer transducer, composed of a PZT layer for transmission and a PVDF-layer for reception, has been constructed to verify and implement this approach. Measurements in a water tank and phantom measurements show that there is a correlation between bladder volume and the harmonic contents within a region of interest (ROI) behind the bladder. The results also demonstrate the usability of the multi-layer PZT-PVDF transducer design for bladder volume assessment on the basis of nonlinear wave distortion dependency.