Category: Case Studies

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

Problem: The client’s proprietary process allows anodized aluminum to survive repeated medical sterilization procedures. However, there was little information documented and the procedure was not standardized. This lack of standardization led to a process window that was ill-defined which produced variable results, a high degree of rework, and customer dissatisfaction.

Solution: Through a series of designed experiments and statistical analysis, the process was reverse-engineered and standardized to ensure a robust window existed for this set of operations to be successful even though it is a manually run process.

Problem: A fixture designed to plate chloride onto silver pins and platinum black on gold pins was suffering from low yields and was in constant need of repair. Plating solution would routinely leak through the base of the fixture and corrode the electronics within. Although the fixture had ten bays, up to six bays were typically down, which required technician intervention to disassemble and re-solder the internal electronics: establishing the plating process as a bottleneck. In addition, the quality of the coating produced was oftentimes rejected by the operators due to surface “defects”, which required nearly a 100% rework rate.

Solution: Given the nature of the process, the threat of leakage was ever-present, so the severity of a leak was reduced. A redesign of the plating fixture moved the electronics to the back of the bays, out of the way of the corrosive solutions. Push-on wire harnesses were used in lieu of the soldering and a modular design was adopted for the fixture, which allowed the operator to quickly change out a bay without tools if it would become inoperable: negating the need for constant technician intervention. A test method validation (Gage R&R) was performed between the operator, process engineers, and R&D to “recalibrate” the operators as to what was acceptable. All these changes resulted in a 67% throughput increase in the platinization and a 75% improvement in first-run yields for the chloridization process.

Problem: The chosen supplier for the balloon fill media (the liquid portion of a Class III PMA medical device) was sourced as an aseptic fill process, resulting in large cash outlay for each batch of materials. This material carried a 4-year validated shelf-life. The desire was to validate terminal steam sterilization without losing the 4-year shelf-life. Product was running low and an expensive revalidation of the aseptic process was coming due.

Solution: A literature search was used to find data to rationalize the idea that the only unknowns for this change were the integrity of the vial seal and the quality of the product after exposure to terminal steam sterilization. These two unknowns were tested and verified to be unchanged allowing for an adoption of the 4-year shelf-life. A terminal steam sterilization provider was identified, and the process was validated all within 7 months. The terminally sterilized product was produced at a third of the cost of the aseptically processed product resulting in a savings of $1MM for the first year.

Problem: The chosen material for the optical window in a laser ablation catheter (a Class III PMA product) was exhibiting a sporadic (<0.05%) but critical defect due to a processing sensitivity in the raw material. The desire was to find a material that did not possess this sensitivity and yet matched the original material in all other properties.

Solution: Using a cross-functional team, the key attributes of the existing material were identified and ranked using a Pugh Matrix to provide guidance on the properties that drove its functionality. Due to the rarity of the defect, significant testing (1200 samples) was conducted through the external component supplier to prove that the alternate material met all requirements. Because the design of the product was not changed, the data gathered were sufficient for a 90-day FDA review and approval cycle.