Update of two dimensional arrays for real time volumetric and real time intracardiac imaging
We have previously described 2-D array transducers with up to several thousand elements operating at frequencies between 2.5 and 5.0 MHz for real time volumetric imaging. Lately, there has been interest in developing catheter based intracardiac imaging systems to aid in the precise tracking of anatomical features and intracardiac devices for improved diagnoses and therapies. We constructed several arrays for real time intracardiac volumetric imaging based upon two different designs; a 13 × 11 = 143 element 5.0 MHz 2-D array for side scanning applications, and a 10 × 10 = 100 element 7.0 MHz 2-D array for side scanning applications. The 5.0 MHz array fits into a 12 French (3.8 mm OD) catheter and the 7.0 MHz transducer is designed to fit into a 9 French (2.9 mm OD) catheter. We also constructed two transducers for transthoracic imaging; a 40 × 40 5.0 MHz 2-D array, and a 40 × 40 7.0 MHz 2-D array. The -6 dB fractional bandwidths for the transducers varied from 27% to 67%. All the transducers were constructed on a 6 layer polyimide interconnect. Both transthoracic and intracardiac volumetric images of ultrasound phantoms and animal models have been obtained using the Duke University real time volumetric imaging system which is capable of generating multiple planes at any desired angle and depth within a pyramidal volume.
