The Shock Response and Suitability of Synbone (R) as a Tissue Simulant

The applicability of various materials as human tissue analogues has been a topic of increasing interest in recent years. It allows for more cost-effective experiments to be carried out, but also avoids ethical issues that would arise from using real human tissue. Synbone (R), a porous polyurethane material, is commonly used in ballistic experiments as a bone simulant, but until now has not been characterised in terms of its dynamic behaviour. Here, the Hugoniot equation-of-state (EOS) for Synbone (R) has been derived via a series of plate-impact experiments; highlighting the importance of the underlying material structure in terms of material collapse under high strain-rates. A compaction model was also used for a more extensive analysis of Synbone (R) and for further comparison of this material to solid polyurethane. This work following on from previous in-house studies of other tissue analogues - has provided useful data for future simulation of this material. In addition, comparison to dynamic data for other tissue and simulant materials has highlighted the importance of considering tissue as non-monolithic; each layer of tissue should ideally be represented by its own simulant in ballistic experiments. The equation-of-state (EOS) of Synbone (R) was found to be U-s = 0.33u(p) + 0.97; u(p) < 0.55 mu m s(-1) and U-s = 13.87u(p)(2) - 14.82u(p) + 5.21; 0.55 > u(p) < 0.95 mu m s(-1), while the compaction Hugoniot curve tended towards the Hugoniot for polyurethane at higher pressures.