Direct Longitudinal Compression

The purpose of this test is to determine the deformation of the device in response to a compressive force applied longitudinally along axis of the device.

Test Procedure

The test sample is positioned on a specific vertical stent fixture. The sample stands vertically with its inferior extremity guided by a specific stent fixture.  A piston, controlled by a stepper motor, is compressing the stent upper extremity at a fixed rate while measuring the compression force. The test stops either when the force reaches a specified force or the stent length reduction reaches 50%. At the end of the displacement, piston displacement and force are recorded.  A video camera or a standard camera can be used to record the stent system behavior during the compression. Stent sample is removed from the fixture, sample final length and diameter are measured using an optical gauging machine and recorded.



Automatic compression / traction system :

– Dynamometer

– Stepper motor


Calibrated Gauge blocks

Thermostatic chamber

Calibrated thermometer

Optical gauging machine

Measured Parameters





Balloon expandable stents

Self expanding stents

Service Levels

Applicable Standards

  • ISO 25539-2:2020
    Cardiovascular implants — Endovascular devices — Part 2: Vascular stents

Related Tests


ViVitro Labs Advantages

Many companies look to academia to handle their testing needs due to the reduced cost. With ViVitro Laboratory Services you gain the following advantages:

ISO 17025 Accredited
For studies used for regulatory approval this is a must. Victoria and Marseille labs accredited by A2LA.

Test Method Validation
The FDA and Notified Bodies around the world are requiring evidence of Test Method Validation. ViVitro Labs has invested significant resources to validate the most common test methods that are not ISO 17025 accredited. We continue to work closely with device manufacturers and share the burden with our clients to validate other specific test methods that are less in demand.

We understand how critical your timelines are. Our expertise and experience ensure your schedule is met and our commitments are delivered on time.

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