Development of a new tissue-equivalent material applied to optimizing surgical accuracy.

The precision of orientation to target placement during invasive therapy is mainly influenced by tool-tissue interaction. In this study, we aim to investigate a transparent Poly (vinyl alcohol) (PVA) hydrogel as tissue-equivalent material which is used in accurate surgical insertion research. The PVA hydrogel with specified formula was prepared by means of physical and chemical crosslink. The effects of chemical composition and synthesis technique on the biomechanical property, density and micro-structure morphology of PVA materials have been investigated in detail. It can be concluded that when PVA concentration is 8 g/dl, the NaCl concentration is 4 wt.%, with mix water/DMSO solvent, prepared under 7 freeze/thaw cycles, the material has the most similar properties with kidney tissue. Experimental results demonstrate that this tissue-equivalent material could be used in the ex vivo insertion accuracy test for robot-assisted percutaneous intervention and surgical training in minimally invasive surgery (MIS).