Axial fatigue tests are performed to axially load material specimens repetitively to evaluate the fatigue resistance of the material. MDT has performed many fatigue tests and developed a wide variety of test fixtures, many of them customized for the particular material or specimen geometry. Some of the tests we have performed and the fixtures we have developed are highlighted below.
These tests demonstrate the device integrity when subjected to axial fatigue for an appropriate post-implantation time period. The Test is performed on an axial fatigue tester with special fixturing to raise the sample count.
This test demonstrates the device integrity when subjected to bending for an appropriate post-implantation time period. A device failure may be defined as any broken or cracked strut visible at 30x magnification during or at the end of the test.
MDT has developed many custom tests around our inventory of axial fatigue testers. Combining the test instrument's axial motion with special fixturing, axial or bending tests can be performed.
These tests demonstrate the device integrity when subjected to flex fatigue (ie: distal tip buckling) for an appropriate post-implantation time period. The Test is performed on an axial fatigue tester with special fixturing. 
These tests provide empirical evidence for the continued structural integrity of percutaneous and transcatheter heart valves when subjected to mechanical fatigue replicating in vivo conditions. The tests are designed to simulate the physiological strain due to the expansion and contraction of the surrounding vessel or the movement of the leaflet. The test is accelerated to obtain results in less time than physiological rates would allow. 
These tests demonstrate the device integrity when subjected to biaxial tension, compression, and or/shear motions for an appropriate post-implantation time period. Fatigue tests are conducted for a minimum of 10 years post-implantation while feasibility or strength characterization tests may be shorter. 
Tensile test fixtures are used for pulling material specimens to failure or for characterizing the material properties after a prescribed loading sequence. MDT has developed a variety of fixtures, many of them customized for the particular material or specimen geometry. The fixtures are designed to be used in either an air environmental chamber or a PBS bath which maintain the temperature and environment at physiological conditions.
Axial fatigue test fixtures are used for axially loading material specimens repetitively to evaluate the fatigue resistance of the material. MDT has developed a variety of fixtures, many of them customized for the particular material or specimen geometry. The fixtures are designed to be used in either an air environmental chamber or in a PBS bath which maintain the temperature and environment at physiological conditions.
Compression test fixtures are used for axially compressing material specimens and components either uniaxially or in fatigue. MDT has developed a variety of fixtures, many of them customized for the particular material or specimen geometry. The fixtures are designed to be used in either an air environmental chamber or in a PBS bath to maintain the temperature and environment at physiological conditions.
Bend Test Fixtures are used to convert the axial motion or rotary motion of the ELF and Instron fatigue testers into various forms of bending motion or motions that combine bending and other motions. MDT has developed many types of fixtures for this purpose and the various designs center on the primary purpose of the test. These fixtures are designed to accommodate a statistically significant number of specimens and are often modified to meet the specific test requirements for the customer's device design. All of these test fixtures can be used with PBS baths or fluid flow to provide physiologically relevant environmental conditions. The attached list of fixtures include descriptions of the types of bending performed. 
The Axial Torsion Fixture combines axial strain on a stent with twisting. These conditions occur in peripheral stenting locations such as the superficial femoral, saphenous, and popliteal arteries. If you don't see the axial fatigue test you are looking for chances are we have already perfromed the test but have not listed it here. Contact us with your testing requirements and we will provide an estimate for creating the axial fatigue test you are looking for.