This benchtop test provides empirical evidence for the continued structural integrity of the devices when subjected to mechanical fatigue replicating in vivo conditions. The test is accelerated to obtain results in less time than physiological rates would allow. The test may be conducted under simulated physiological conditions with saline at 37°C.
The testing objective is to meet the appropriate requirements, as identified by the device manufacturer, and may include ISO guidelines (25539-1, 7198:1998, and 99128) for in vitro mechanical fatigue. Tests will demonstrate the device integrity when subjected to biaxial tension, compression, and or/shear motions for an appropriate post-implantation time period. Fatigue tests will be conducted for a minimum of 10 years post-implantation while feasibility or strength characterization tests may be shorter. A device failure is defined by the device manufacturer. The device manufacturer will also examine the devices post-testing against the acceptance and/or failure criteria.
While MDT biaxial test systems are designed to accomodate a wide range of testing applications, the systems are best suited for characterizing the mechanical properties of natural and artificial tissues. These biomaterials include:
MDT realizes that tissue tests often have rigorous requirements that include complex loading conditions, varied testing motions and conditions, and custom gripping. MDT's planar biaxial durability systems are designed to meet these advanced requirements while maintaining a high degree of precision, accuracy, and repeatability.
MDT groups four of the Bose ElectroForce linear motors on a baseplate (each motor 90 degrees apart) and configures one load cell for each axis of loading (two axes total). A heated, saline bath may be secured to the baseplate to provide a physiological environment. MDT also has the capability to verify strain measurements using a digital high speed camera in combination with state-of-the-art video measurement software.
MDT recognizes that soft biological materials require advanced gripping. MDT uses custom clamp-style plates or hook grips depending on the specimen size and material. Customer-supplied grips and fixtures can also be integrated for specialized applications.
MDT tests are conducted in accordance with ANSI/ISO/IEC 17025-2005. Testing schedules and resource needs are determined during project kickoff meetings with MDT engineers and the customer. Services are performed in accordance to standard operating procedures and test protocols specific to the project. For feasibility or non standard tests, MDT will develop a method and protocol with the customers input and will review the final process with the customer prior to initiation of the test.
MDT offers several inspection methods including:
The test equipment software monitors the cycle count, displacement, and pressure throughout the duration of the test. MDT engineers monitor the test daily and record the temperature for the system. MDT sends weekly updates to ensure customers are apprised of the status of their test. Updates include raw data collected throughout the week for the customer’s analysis.
MDT tests are conducted in accordance with ANSI/ISO/IEC 17025-2005. In compliance with this standard, MDT test reports include comprehensive documentation and summary of the test protocol and results. All tests are GLP compliant and can be submitted directly to regulatory agencies. Any test method deviations, additions, or exclusions are documented and reviewed with the customer prior to beginning the test. Information within the report includes the specific test conditions, statements of compliance with test protocol and the estimated measurement uncertainty. The reported results only relate to the items tested. Any opinions and interpretations provided will be clearly marked as such in the test report. Additional information required by customer-specific methods will also be noted. At the conclusion of the test, MDT provides the customer with a Microsoft Windows formatted CD containing copies of all raw data, inspection results, and other information collected during the test (see example test reports).
Please take a few moments to tell us more about your device and test requirements in our short questionnaire, and we will be happy to provide you with a quote.