A system for assessing occlusion of a region to blood flow includes a catheter with an inflatable member, a first electrode configured for placement upstream of the inflatable member and the second electrodes configured for placement downstream of the inflatable member, the inflatable member configured for inflation to occlude the blood flow through the region. The system further includes a current/voltage source, a resistor and a voltmeter, wherein these components along with the first and second electrodes are configured to form an impedance measuring circuit configured to detect a change in impedance for indicating occlusion of the region to the blood flow.