Medical Device Integrated System Accelerated Life Testing

Abstract

This paper defines the accelerated life test design and technique to evaluate medical device system reliability. The proposed method includes developing system functional diagram to capture the overall ecosystem of the device and all control and noise factors that affect device performance. The test simulates real life therapy level stresses including temperature, patient use, disposable setting, power source alterations, medical prescription and duty cycle. These operation elements are used at different rates to balance the aging of different subsystems and rate of different failure mechanisms. The sample size of the test units is determined based on minimizing the overestimation error of the Mean Time Between Failure (MTBF) value. All observed events, and failures are categorized, and identified as failure per the expected complaint handling systems in real life. The test/tester setup errors and customer errors can also be tracked separately in the test and a mechanism of feeding back to human factors analysis, manufacturing, and service departments are identified to help optimize and inform product design and sustaining engineering activities. Test results and findings are to be compared to field data and benchmarked against a predicted number of failures based on the reliability requirements analysis established prior to product release. Test data and performance parameters are to be tracked and used to establish and optimize proactive and predictive maintenance interval and strategies for limited life and degrading components. Finally, a standardized testing method is to be revised based on lessons learned, and to be generalized for future product tests.