Mechanical characterisation of kidney tissue by dynamomechanical analysis

Introduction The development of realistic organ models for surgical training requires an understanding for their mechanical properties. This paper presents a preliminary dynamomechanical analysis (DMA) study carried out on porcine kidney tissue. Material and Methods Six kidneys were initially obtained from three porcine models. To preserve their mechanical properties they were deep-frozen at -80°C. The tests were performed using the TA Instruments Discovery 20 Hybrid Rheometer (DHR-20). After thawing, the kidneys were sectioned into 25mm long, 10mm wide, and 5mm thick specimens. These specimens were subjected to tensile testing for 660 seconds at a separation speed of 50µm/s. Results After carrying out different tests, the preliminary results indicated a reduction in the initial force applied to stretch the fabric. This force initially decreases, reaches a specific point, and subsequently increases until the fabric breaks. This decrease in the force required to stretch the fabric may be attributed to a process of initial settling of the fabric, which, once overcome, begins to oppose resistance, thereby increasing the force used to stretch it until rupture. Conclusions The initial results suggest that the renal tissue exhibits an initial soft phase and followed by a hardening phase until rupture. Given that these are preliminary findings, further tests are planned to obtain a comprehensive characterization.