Digital Data Output for ISO 8536-8 IV Leakage Testing

Overview

B Braun Medical is a leading manufacturer of IV therapy solutions. To meet International Standards Organization (ISO) standards for safety, B Braun IV sets must pass several rigorous tests for leakage. Our team has been tasked to develop new processes to develop digital data while carrying out three different ISO leak standard tests: ISO 8356-8 A.3.2, A.3.3, and A.3.4. For the A.3.2 and A.3.3 leakage tests, B Braun seeks a method of outputting digital data that can support pass/fail determination of their IV sets. For the A.3.4 leakage test, B Braun seeks a testing apparatus that can maintain the temperature of water at 40°C inside an IV set for fifteen minutes.

Objectives

– ISO 8356-8 A.3.2 Leakage Standard: Involves pressurizing an IV with air, then dunking the set in water for fifteen seconds and looking for air bubbles leaking into the water. As a deliverable, B Braun would like a new testing method that satisfies the ISO standard and would allow digital data output that can support pass/fail determination of their IV sets.

– ISO 8356-8 A.3.3 Leakage Standard: Involves filling an IV with water, then pulling a vacuum on the set for fifteen seconds and looking for air ingression into the IV set. As a deliverable, B Braun would like a new testing method that satisfies the ISO standard and would allow digital data output that can support pass/fail determination of their IV sets.

– ISO 8356-8 A.3.4 Leakage Standard: Involves filling an IV set with water, placing the set on a table, and looking for water leakage for fifteen minutes. As a deliverable, B Braun would like a testing apparatus that can be used to keep water at 40°C inside an IV set for the duration of the fifteen-minute leakage test.

Approach

– A.3.2 Project: The approach taken to satisfy the A.3.2 deliverable involves using the natural buoyancy of an air bubble in water, coupled with a commercial bubble detector, to digitally sense the presence of leaks. In this design, the IV set is placed in a specially built container that is filled completely with water. This container has gently sloping walls that lead to a bubble sensor at the very top of the system; this way, any bubble released by a leaking IV set is guided to the bubble detector to be sensed. The bubble detector then sends a digital signal to a computer that records the presence of a bubble.

– A.3.3 Project: The approach taken to satisfy the A.3.3 deliverable involves carefully monitoring the force required to pull a syringe attached to an IV set to a prescribed vacuum pressure. By attaching a force gauge to the piston of a syringe, the exact force required to reach a certain vacuum pressure can be observed. Then, if the IV leaks and air ingresses into the set, the force required to hold that prescribed pressure will decrease, providing digital evidence of a leak.

– A.3.4 Project: The approach taken to satisfy the A.3.4 deliverable involves placing the IV set inside a large polycarbonate tube with a polyimide heater adhered to the wall. This heater, whose output is controlled by an AC transformer, has been tuned such that its heat output will maintain the temperature of the water inside the IV set at 40 ±1°C. Additionally, the outer tubing has expandable grommets that allow transfer of the IV set in and out of the testing apparatus while minimizing heat loss to the surroundings.

Outcomes

– A.3.2 Project: Testing has shown that this setup design is effective at detecting bubbles produced by a leaking IV set. With this test method, B Braun can get digital, objective results to the A.3.2 leakage test that they can provide the FDA to prove compliance with ISO standards.

– A.3.3 Project: Testing has shown a substantial difference between the force decay caused by a leaking IV set and a fully secure IV set. These results prove that the concept of using a force loader to find leaks is feasible. With this test method, B Braun can get digital, objective results to the A.3.3 leakage test that they can provide the FDA to prove compliance with ISO standards.

– A.3.4 Project: Testing has shown IV water has been kept at a consistent 40 ±1°C after fifteen minutes of testing, as prescribed by the ISO standard. With this test setup, B Braun can have confidence that the leakage testing they carry out effectively meet the A.3.4 ISO standard.