A Real-time Color Doppler Marker for Echocardiographic Guidance of an Acoustically Active Extracorporeal Membrane Oxygenation Cannula.

B-mode ultrasound imaging guidance of cannulas can be compromised by noise, artifacts, and echogenicity that is not distinctive from that of surrounding anatomy. We have modified a venovenous extracorporeal membrane oxygenation cannula by embedding piezoelectric crystals into each of its 3 blood flow ports. Each vibrating crystal acoustically interacts with a Doppler imaging signal and produces an instantaneous color marker. The aim of this study was to compare identification of the extracorporeal membrane oxygenation cannula ports by B-mode imaging versus the color Doppler marker. Unlike B-mode imaging, the color Doppler marker identified the corresponding port even in highly challenging closed-chest scans in anesthetized pigs. The method could improve guidance accuracy of cannulas by ultrasound scans.