Integrated catheter for 3-D intracardiac echocardiography and ultrasound ablation

A catheter device with integrated ultrasound imaging array and ultrasound ablation transducer is introduced. This device has been designed for use in interventional cardiac procedures in which the cardiac anatomy is first imaged using real-time three-dimensional (3-D) ultrasound, then ablated to treat arrhythmias. The imaging array includes 112 elements operating at 5.4 MHz arranged in a 2-D matrix. Individual elements have a bandwidth of 21% and an insertion loss of 80 dB. The array has an azimuth resolution of 12 degrees and an elevation resolution of 8.7 degrees. The ablation transducer is a concentric piezoelectric transducer PZT-4 ring (outside diameter (O.D.), 4.5 mm, inside diameter (I.D.), 3.1 mm) operating at 10 MHz that surrounds the imaging array. It can produce a spatial-peak, temporal-average intensity up to 16 W/cm2. The entire device fits into a 9 Fr lumen with a 14 Fr tip to accommodate the ablation ring. With this device we have imaged, in realtime 3-D, a variety of targets including wire phantoms, fixed sheep hearts, and fresh bovine tissue. The ablation ring has been used to heat tissue-mimicking rubber 14 degrees C, as well as create lesions in fresh bovine tissue.