Impedance devices for obtaining conductance measurements within luminal organs. In at least one embodiment of an impedance device of the present disclosure, the device, comprises an elongated body and an detector positioned upon the elongated body, the detector comprising at least five electrodes and configured to obtain one or more conductance measurements generated using a first arrangement of four of the at least five electrodes and further configured to obtain one or more fluid velocity measurements using a second arrangement of four of the at least five electrodes when the elongated body is positioned within a fluid environment of a mammalian luminal organ, wherein the first arrangement is different from the second arrangement.