Using robotic systems in order to determine biomechanical properties of soft tissues

Biomechanical properties of soft tissue are important not only during computer simulation for medical training but also for systems where tissue deformation must be estimated in real-time, for example, Robot Assisted Surgery. The purpose of this paper is to describe some biomechanical tests consisting in the measurement of contact forces and deformations in tissue phantoms and porcine soft tissues (liver, brain, stomach and intestine). During the measurements two different procedures were applied. First, we have used a 5DOF micromanipulator instrumented with a spherical probe and a 6-axis force/torque ATI sensor. In the second procedure instead of the micromanipulator a Stäubli RX60 robot was used to apply the force over the samples. During this last test a high noise-signal relationship was detected and in order to improve the accuracy of the experiments some results were obtained using a Stäubli TX40 robot. Major accuracy in research in the field of soft tissue could be reached using standard procedures. Robotic systems allow precise movements to carry on biomechanical tests, and also permit a wide range of tasks to be implemented.