In the present work the first results of the electronic implementation of a transit-time electronic system is presented. The system is conceived for obtaining the sanguineous volumetric flow in a vessel and the first laboratory data measured in its calibration with a phantom. Some tests have already been made in heart coronary bypass procedures. The system uses the detection technique known as Transit-time flow measurement (TTFM), adapted for specific graft flow, and is compounded for an analogical module, an acquisition-conversion unit and a portable PC computer. The analogical module senses the flow, by an ultrasonic bi-transducer probe, and transforms it into voltage variations by processing. The acquisition-conversion module is based on a microcontroller that transforms voltage variations in PC-accessible data through an USB port. The control & processing software has been developed in LabView. This work is part of the CYTED multinational project "Ultrasonic and Computational Systems for Cardiovascular Diagnostic" (SUCODIC), the first Consortium Project of the Ibero-American Program CYTED.