In-vivo characterization of soft tissue is a key step towards accurate biomechanical simulation enabling planning and intra-operative assisted surgery. This chapter presents the new version of LASTIC, a device measuring soft tissue deformations using a negative pressure. Its capabilities are compared with standard tensile tests on five samples with different elastic properties, i.e Young modu-lus, from 10 kPa to 1 MPa, in order to estimate its accuracy and define the functional measurement range. Results show that LASTIC overestimates Young modulus by an average of 24 % compared to the tensile devices. This error, although rather large, allows a first estimation of the elastic modulus of different materials, especially living tissues, even during surgery. Directions for improve-ments are given that will allow for better patient-specific biomechanical simula-tions of soft tissues.