Just a general technology question for the forum.  I am ordering new ultrasound equipment for our surgery center.  There have been recent advances allowing for hand-held US technology, such as the Sonosite iVis, Android, and Ipad devices.  However, I don't see any handheld US equipment which can measure fistula flow / pulse wave doppler.  I evaluate new fistulae by US to access maturation and measure flows.

Does anyone know if there are any hand-held US devices which can measure flow?  Thanks.