MEDISTIM VeriQ system                           

The Medi-Stim VeriQ system is designed to meet the growing demand for intra-operative quality control and documentation of surgical procedures.  

Well-established ultrasound principles such as Transit Time Volume flow and Doppler velocity measurements have been adapted to meet specific needs in the operating room. Probes utilizing transit time and Doppler have been combined to optimise graft placement and assessment. A start-up time of less than 30 seconds and a reduced need for user interaction means that use of VeriQ adds only minimal time to the surgical procedure. A large 15" LCD touch screen with an intuitive user interface displays all significant parameters and is easily readable, even from a distance. The new hardware platform allows for four flow, two pressure and two auxiliary channels in addition to the new X-plore channel. Every measurement is saved in a dedicated, high capacity patient database, keeping record of all measurements and data entered for each patient. Hardcopy reports for the patient notes can be produced easily within seconds by the on-board colour printer, or exported to the CD-Rom/floppy in HTML format for easy distribution to the hospitals computing network.

TRANSIT TIME PRINCIPLE

The Transit time probes surround the vessel, generating a uniform ultrasound eld across the vessel lumen. Ultrasound pulses are transmitted from the crystals on
each side via the reector and back to the crystal on the opposite side. The transit time is measured for each pulse, and the dierence in transit time between the
pulse going upstream and the one going downstream is proportional to the volume of ow passing through the probe. Q  t2 - t 1 A range of dierent probes are available for vessel diameters from 1,5 mm up to 35 mm.

DOPPLER PRINCIPLE

When an ultrasound beam is reected by a moving object, the frequency of the transmitted pulse is changed. An object moving towards the ultrasound beam will compress the waveform and increase the frequency, and accordingly an object moving away from the beam will lengthen the waveform and decrease the frequency. The change in frequency, also called Doppler shift, represent the velocity and direction of the moving target. To limit problems related to the ultrasound
beams angle of the incident with the blood, the X-plore probe has an inbuilt angle of 45 degrees. Holding the probe perpendicular to the vessel direction will ensure accurate velocity measurements.