New ring array transducers for real-time 3D intravascular ultrasound

We have developed new miniature 2D array transducers integrated into a Cook Medical, Inc. vena cava filter deployment device. One transducer consists of 55 elements operating near 5 MHz. The interelement spacing is 0.20mm. It was constructed on a flat piece of copper clad polyimide and then wrapped around an 11 French catheter of a Cook, Inc. inferior vena cava (IVC) filter deployment device. We used a braided wiring technology from Tyco Electronics Corp. (Wilsonville, OR) to connect the elements to our real-time 3D ultrasound scanner. Typical measured transducer element bandwidth was 20% centered at 4.7 MHz and the 50 Ohm round trip insertion loss was -84 dB. The mean of the nearest neighbor cross talk was -37.0 dB. We have also built a transducer on a 46 cm long single layer flex circuit from MicroConnex (Snoqualmie, WA) which terminates in an interconnect that plugs directly into our system cable. This transducer consists of 70 elements at 0.157 mm interelement spacing operating at 4.8 MHz. Typical measured transducer element bandwidth was 29% and the 50 Ohm round trip insertion loss was - 94 dB. The mean of the nearest neighbor cross talk was -33.0 dB.