A method for applying a plurality of compressive forces to a thorax of a patient, measuring a displacement corresponding to each of the plurality of compressive forces, and determining properties of the thorax based on the compressive forces and the displacement. A system having a force applying device applying compressive forces to a thorax of a patient, a measurement device measuring a displacement of the thorax corresponding to each of the compressive forces, and a control device determining properties of the thorax based on the displacements of the thorax corresponding to each of the compressive forces.