Evaluation of the mechanical properties of human liver and kidney through aspiration experiments.

A proper mechanical characterization of soft biological tissues of the human body has a strong impact on several medical applications such as surgical planning, virtual reality simulators, trauma research, and for diagnostic purposes. Adequate experimental data are needed to describe quantitatively the mechanical behaviour of those organs. We present a technique for the acquisition of such data from soft tissues and its post processing, based on a continuum mechanics approach, to determine some parameters of the tissue's mechanical properties. A small tube is applied to the target organ and a weak vacuum is generated inside the tube according to a predefined pressure history. A video camera grabs images of the deformation profile of the aspirated tissue, and a pressure sensor measures the correspondent vacuum level. The images are processed and used to inform the fitting of uniaxial and continuum mechanics models. Whilst the aspiration test device is suitable for in vivo applications, under sterile conditions during open surgery, we hereby present first results obtained by testing cadaveric tissues.