ADMET testing systems are trusted by leading medical device manufacturers, universities, and research laboratories to determine the mechanical properties of biomedical materials and products in vitro. We offer a wide range of systems capable of simulating real-world conditions and performing tension, compression, flexural, adhesive, torsion, biaxial, and fatigue tests to ASTM and ISO standards. Our ability to custom design a system to fit specific needs allows us to provide testing solutions for virtually any medical application.
Over the last few years ADMET has been approached to solve dozens of biomedical material testing problems. Below we have selected five stories from our recent successes to highlight what is possible using ADMET technology.
1. How Do You Measure The Strength of Welds?
A leading stent manufacturer wanted to measure the strength of welds used in its stents but was having difficulty achieving consistent results. In addition, it took approximately 20 minutes to test each weld.
ADMET’s solution was to employ it’s 45N MicroTester in horizontal orientation with specially designed grips that isolate a single weld. The grips ensured that the wire adjacent to each stent was clamped the same way each time and that the force applied to the weld was perpendicular to weld at the joint. ADMET’s MTESTQuattro controller was used to load the welds at 1mm/min and an inexpensive 200x microscope was also incorporated with the controller to record weld failure modes. Prior to ADMET getting involved, the stent manufacturer was using a universal testing machine from a competitor with their own grip design. ADMET’s solution reduced the test time for each weld from 20 down to 3 minutes and reduced the variability of results by a factor of 5.
2. How Do You Detect Cancer Using The Modulus/Stiffness Of Biopsy Samples?
Researchers at a government agency wanted to measure the modulus/stiffness of healthy and cancerous biopsy samples to determine if it is a viable means of detecting cancer. For their studies, the researchers wanted an easy to use portable instrument that could be quickly setup at each hospital site.
ADMET’s solution included a 45N MicroTester equipped with the standalone eP2 Digital Controller. The system featured a top mounted actuator with nm resolution, a 250 g load cell, and compression platens. The lower compression platen included a raised lip so samples could be tested wet. With the push of a button, the eP2 would load the samples to a user specified force at a specified displacement rate. At test completion, the eP2 would automatically measure and report the sample stiffness and return the crosshead to its starting position. The compact ADMET MicroTester fits in a rugged carrying cased with wheels for easy transport between labs.
3. How Do You Determine The Durability Of Compounds Involved In Stabilizing Bone Fractures?
A medical device company focused on minimally invasive solutions for the treatment of bone fractures needed a torsion testing system to determine the durability of their bone stabilization/fixating materials.
ADMET supplied a fatigue rated 30Nm eXpert 81T capacity horizontal Torsion Testing System equipped with the MTESTQuattro Controller. The eXpert 81T featured a reaction torque transducer mounted on a sliding tailstock. Both the drive spindle and tail stock included grip plates to accommodate the clients custom designed grips. A dead weight pulley system was also included with the tester for applying constant tensile or compressive loads to the test samples. Test regimes included the application of torque or angle sinewave amplitude controlled profiles for up to 5 million cycles at frequencies up to 10Hz.
4. How Do You Measure The Mechanical Properties of Bone Screws?
A spinal implant company required an axial-torsion test system for measuring the mechanical properties of their bone screws according to ASTM F543 Annex A1, A2 and A4. ADMET provided an eXpert 8602 Axial Torsion Testing System equipped with the MTESTQuattro Controller. A collet holder with a variety of collet sizes were supplied for fixing the screws in place for determining the Offset Yield Torque, Maximum Torque, and Angle at Break according to Annex A1. A centering vise was incorporated for holding test blocks to determine insertion and removal torques according to Annex A2 and the self-tapping performance of self-tapping medical bone screws according to Annex A4.
5. How Do Cells Sense And Respond To Mechanical Signals?
Mechanobiology focuses on the way that physical forces and changes in cell or tissue mechanics contribute to development, physiology, and disease. A major challenge for scientists is understanding the molecular mechanism by which cells sense and respond to mechanical signals.
Several leading universities have turned to ADMET’s BioTense Bioreactor for performing studies in mechanobiology. The BioTense Bioreactor incorporates a tensile stage inside a small volume perfusion bioreactor. A variety of grips are offered for holding various types of scaffolding materials. ADMET’s MTESTQuattro Controller can be programmed to apply cyclic or ramp and hold force or strain control profiles. The BioTense is designed to sit atop an inverted microscope and the bioreactor’s integral viewport enables high magnification observations of cellular activity. The BioTense’s unique design allows cells to proliferate and live for several weeks thus allowing for studies to be conducted over long periods of time.
These stories demonstrate the breadth of issues that leaders face in the Biomedical sector. For more details on all of these solutions and many more, don’t hesitate to reach out to our Director responsible for the Biomedical sector, Vinny Milano.