ISO 11491:2017 pdf free
ISO 11491:2017 pdf free.Implants for surgery – Determination of impact resistance of ceramic femoral heads for hip joint prostheses
This document can be used for the purpose of material development, material comparison, quality assurance, implant system characterization, reliability analysis and design data generation.
Impact resistance (cyclic strength) is determined by applying impacts of increasing energy to the head/taper construct and identifying the maximum energy that does not result in fracture.Alternatively, the impact load (cyclic strength) may be determined by quasi-static load-release cycles identifying the maximum load that does not result in fracture.
NOTE These test methods are most appropriate for evaluating new types of ceramic ball head material in combination with metal stem tapers as well as new taper design specifications by comparing them with clinically established and proven ceramic ball head and metal stem taper systems.
The test machine shall have a stiff structure capable of applying an impact to a test specimen by a falling/drop weight. The machine shall be firmly mounted on the ground or a heavy, rigid bench (e.g.granite or steel topped measuring table). The machine shall accommodate a weight of adjustable mass to fall onto the sample from adjustable height to allow the application of a range of impact energies. The weight can be guided or free. Any guiding mechanism shall minimize friction. The guiding mechanism should not be in contact with the striking assembly. The test specimen composed of a head and neck unit shall be supported on a holding block mounted on a load cell. The axis of the falling weight, the test specimen, the holding block and the load cell shall be aligned vertically (±1°) and laterally (±1 mm).Fixturing to position the test specimen shall have low mass, but shall be stiff and strong enough to withstand repeated impacts.One example of the test machine is shown in Figure 1.ISO 11491 pdf free download.
