Abstract: A blood flow calibration system 500 including a computer 400 operable to determine and store calibration data for a flow meter 124, a test system 530 operable to simulate blood flow for the flow meter 124, thereby allowing the computer 400 to determine the calibration data, and a programmer 300 operable to transfer the calibration data from the computer 400 to the flow meter 124. The flow meter 124 preferably includes a power management circuit 348a,b operable to detect whether the flow meter 124 is powered. In the event that the flow meter 124 is unpowered, the power management circuit 348a,b is preferably able to supply power to a portion of the flow meter 124 in order to transfer the calibration data thereto.