The purpose of this project is to create a mechanical model of the human thorax that will allow for benchtop testing of automated resuscitation devices which provide mechanical chest compressions (mCPR). Important properties that affect the motion of the human thorax are the elasticity constant and viscous damping coefficient. Current models used for testing only simulate the elasticity through the use of a linear spring. This new design adds pneumatic dampers in addition to the springs to add the element of nonlinearity. Sensors will also be integrated into the system to collect force and displacement data. This will provide real-time feedback on the chest compressions as well as information for a feedback system that can change the damping coefficient in real-time. The effectiveness of this model will be demonstrated by plotting its force-displacement data using mCPR devices and validating the data against clinical research of the physiological behavior of the human chest.