Advances in two dimensional arrays for real time 3D intravascular ultrasound

We have previously described 2D array transducers for forward looking real time 3D intravascular ultrasound (IVUS). We developed two forward-viewing transducers. The first is a 14 French catheter transducer intended to guide the placement and retrieval of devices in the peripheral vessels. It operates at 5 MHz and features 112 active channels in a 10×14 array. This transducer was originally designed for intracardiac echo applications. The second is a 5 French catheter transducer for use in smaller vessel. It operates at 10 MHz. and the array is 11×11. Our earlier processes led to poor yield and image quality. A new process, based on a custom fixture, improved the flatness of the wireguide. This improved our bonding and dicing techniques and increased our yield by 50%. Real time 3D images have been obtained from both phantoms and actual hearts. We have also pursued the fabrication of another 2D array transducer that was constructed with non-rectilinear element placement. Using the same cabling, 61 elements were diced out with a laser. Preliminary pulse and spectrum show a -6 dB bandwidth of 55% centered at 13 MHz.