Test Methods for Catheters and Medical Tubing

Medical catheters are typically inserted into canals, vessels, passageways, or body cavities to inject or remove fluids from the body. Applications include drug delivery, urology, neuromodulation, balloon angioplasty, dialysis, and more. Failure of these devices can result in severe patient injury. As a result, mechanical testing is used for research and development purposes, as well as quality control. Mechanical testing is also required by the Food and Drug Administration’s (FDA) guidance documents to demonstrate device safety.

Breaking strength of the tubing is a critical measurement of product quality. In addition, it’s imperative to test the catheter’s frictional forces during insertion and removal from the body. ISO 1055-1 outlines general requirements for testing intravascular catheters.

The challenges of testing catheters and medical tubing are:

• Finding a gripping solution that does not cause jaw breaks
• Testing at body temperature
• Having a low force system with sufficient travel for tensile testing
• Low force load cell for frictional testing
• Flexible software that can conduct both tortuosity tests for friction measurements, as well as standard tensile tests

Instron® Solution:

• Finding a gripping solution that does not cause jaw breaks – Instron offers pneumatic cord and yarn grips that are highly effective at preventing slippage and reducing the clamping stress applied to the specimen. The reduced clamping stress helps prevent jaw breaks.
• Testing at body temperature – For testing at body temperature, Instron offers the BioBox, which can surround a single column 5900 Series or 3300 Series system for testing at 37°C.
• Having a low force system with sufficient travel for tensile testing – The 5944 model is a low force test system that also has sufficient travel for testing high elongation catheters.
• Low force load cell for frictional testing – For tortuosity testing, Instron offers a catheter test system that enables the frictional forces of a catheter or piece of medical tubing to be quantified. The system is a 5900 Series test system, mounted horizontally, that utilizes two low force load cells to average force measurements during testing. The catheter test system enables simulation testing of how a doctor, nurse, or surgeon would insert the catheter into a patient’s body.
• Flexible software that can conduct both tortuosity tests for friction measurements, as well standard tensile tests – Bluehill® Universal software enables users to conduct both standard tensile tests of catheters, as well as frictional tests on catheters using a horizontal test system.