CONDITION MONITORING OF ROTARY BLOOD PUMPS

Long-term, trouble-free operation of ventricular assist devices (VADs) is critical to the patient. A catastrophic failure of the VAD could c ost the patient's life, thus defeating the purpose of the device. The targeted 90% 5 year reliability also implies that the average device l ife would exceed the 5 year limit. Time based explantation of the devi ce after the fifth year will replace many devices with significant add itional life, subject the patient to unnecessary surgical risk, and in crease costs. To preclude the need for time based replacements and pre vent catastrophic failures, a condition monitor is proposed in this ar ticle for early detection of faults in VADs. To develop this monitor, the effectiveness of various sensing and monitoring methods for determ ining the VAD condition is investigated. A Hemadyne pump was instrumen ted with a set of eight sensors, and a series of experiments were perf ormed to record and analyze signals from the normal and abnormal pumps with five different faults. Statistical, spectral, envelope, and ense mble averaging analyses were performed to characterize changes in sens or signals due to faults. Experimental results indicate that statistic al and frequency information from the acceleration and dynamic pressur e signals can clearly detect and identify various VAD faults.