Problem: A pressure-decay leak tester was set up to ensure that the balloon catheters being tested were air-tight. The procedure was not only long (> 4.5 minutes), but generated a large percentage of false failures, requiring retests.
Solution: Using the design requirements for the catheter water leakage rate coupled with the ASTM standard for catheter leak rates, a series of experiments and acceptance criteria were developed to identify air leakage by immersing the catheter in water during testing. The outcome of the experiments was that the leak testing dwell phase could be reduced from 120 to 15 seconds and still catch all failures. The new set of conditions for the dwelling phase was decreased to 30 seconds to have a safety factor of 2X