Cardio Pulmonary Resuscitation (CPR), especially chest compression, should be performed promptly on victims of cardiac arrest for improved morbidity. CPR is performed in 2 steps, chest compression and chest ventilation. But, commercially available CPR mannequins do not accurately mimic the viscoelastic properties of the human chest, resulting in poor CPR performance. We propose a CPR mannequin which exhibits a chest with increasing stiffness as the depth of compression is increased; the increased bio-fidelity of this mannequin should improve CPR training efficacy. This mannequin also measures depth and rate of compression, the air volume during chest ventilation, and compares the measured values against acceptance criteria that can be tuned to different standards. © Springer-Verlag London 2013.