Acoustic Emission on Human Femur Tissue Fracture

This study describes the acoustic emission (AE) activity during fracture of human femur tissue under flexural load. The sample is fixed as a cantilever and two AE broadband sensors are placed in different points of the sample, one near the fixing end and the other near the head, where a pin load is applied. The aim is to investigate if AE procedures and indices well established in engineering materials characterization can also offer valuable insight to the fracture of a material as complex as the femur. Preliminary analysis shows that parameters like the number of acquired AE signals and their amplitude correlate well to the load history. Human bone tissues are known for their brittle nature, allowing nearly no visible signs of cracking until the final failure. However, AE detects the fracture of human tissue from the early micro-cracking events that occur at loads less than 20% of the ultimate, enabling monitoring of the whole fracture process. Additionally, source location correctly identifies the zone of fracture much earlier than the visual cracking appears. Frequency and waveform shape parameters are connected to the pattern of the bone fracture. Study of the samples by AE can increase the understanding of its fracture behavior providing information that is difficult to obtain with any other monitoring technique.