Bone Fracture Detection by Electrical Bioimpedance: Measurements in Ex-Vivo Mammalian Femur

To simulate a limb, two phantoms of bovine femurs (one with an intact bone and the other with a bone sawn in two) were constructed and non-invasive Electrical Impedance Spectroscopy measurements were taken on them in order to identify differences in their respective Cole Cole diagrams. Impedance spectroscopy was performed by a frequency sweep between 1 Hz and 65 kHz at a fixed current of 1 mA. The results obtained show wide differences in the Cole Cole diagrams of both phantoms (intact and fractured bone), especially concerning the real component of the impedance, which was always lower in the fractured femur than the whole one around the bones’ section corresponding to that of the lesion in both femurs. These superficial (non-invasive) measurements correspond to the base measurements of electrical impedance spectroscopy and they could, in turn, correspond to what occurs in mammals immediately after a fracture occurs, i.e. a dramatic increase in electrical conductivity due to the diffusion into the fracture site of more conductive materials such as the blood and the extravascular fluids.