Nitinol


	NiTinol Nitinol: Titanium/Nickel alloy Memometal has been working with Nitinol since 1986. More than 20.000kg have been produced Binary alloy 50%Titanium / 50%Nickel (vitually atomically equal) Rate of impurity < 0.1% Properties → Shape memory Shape memory is used for staples: the feet and back of the staple become maleable through heating or at body temperature Shape change temperature is variable from -20°C to +100°C Hot shape memory: changes shape at 50°C Warm shape memory: changes shape at 35°C Cold shape memory: changes shape at 20°C Force from 10 to 40kg/mm² For a staple weighing 2 to 8 kg depending on height Distortion: 4% → Superelasticity Superelasticity is used for staples and anchors: the part naturally adopts its shape after implantation Great elasticity with constant force Purely elastic distortion up to 8% → Biocompatibility Nitinol is inert: Nickel on its own is toxic, but a think layer of titanium oxide shapes on the surface creates a barrier against the nickel Long-term biocompatibility is proven: ISO 10993 standard ASTM F 20 63 standard specific to Nitinol Bibliography (biocompatibility evaluation of nickel-titanium shape memory alloy by J. Ryhänen) → IRM compatibility IRM compatibility has been proven through a study performed at the Laboratoire de biomatériaux en site osseux (laboratory of osteo-biomaterial) and the laboratoire de résonance magnétique en biologie et médecine (laboratory of biological and medical magnetic resonance) at the University of Rennes Rules of use of the MEMOMETAL implants: Storage and transport at room temperature (even up to a temperture of 60°C) Storage prior to surgery: Cold memory: < -20°C during 2 hours minimum Warm memory: <0°C during 2 hours minimum Hot memory: room temperature Superelastic: room temperature Heating the implant: Cold memory: body temperature Warm memory: body temperature Hot memory: electric scalpel beated to 50°C Superelastic: body temperature