In Cardio-Vascular X-ray systems, X-ray tubes are susceptible to wear to a very large extent. It is likely that the tubes fail before the economical lifetime of the system has passed. The dominant factor in deficiency of the tubes is usually the cathode filament wear. In the presence of the filament wear as a result of evaporation of the tungsten, the tube properties such as filament resistance change due to the shortening of tungsten diameter at some point along the filament. As the resistance decreases, the emission current of the filament deviates from its predicted value. Besides, the decrease in filament diameter results in filament break down. In this assignment, a method is proposed and evaluated to predict approximately when the filament is close to failure. The method indirectly employs and analysis the tangent of the resistance change to the amount of wear induced to the filament in exposure runs. The method is evaluated on two tubes and in two configurations. In the first configuration, the lifetime test is performed under a complete cardiovascular system setup. Since the cardiovascular test system was not available later, a new configuration for the lifetime tests on the second tube was developed. The second configuration is a simulated version of the cardiovascular test system with the help of Labview and Java. According to the life time test results, the method has the potential to be commercially used and implemented in the X-ray systems upon diagnosing the bugs in the generator which caused spikes and noise in the results. Other main outcomes of the project are: