VeriQ – Intraoperative TTFM and doppler velocity measurementsVeriQ™ offers both proven transit time flow measurement (TTFM) and Doppler velocity measurements that are specifically designed for intraoperative blood flow and graft patency verification. Transit Time Flow Measurement (TTFM) should be used to verify graft patency, as recommended by guidelines issued jointly in 2010 by the European Society of Cardiology (ESC) and European Association for Cardio-Thoracic Surgery (EACTS).