CPRmeter is a measurement and feedback device for professional use during chest compressions on cardiac arrest victims. Clinical research has shown the need to improve CPR quality to save more lives. The CPRmeter is placed on the chest of the patient and guides the user to correct compression depth and rate through a dynamic visual interface, based on advanced calculations of depth and force data. Through extensive user testing, the CPRmeter is designed to provide relevant and balanced feedback for both experienced and infrequent users in a challenging, stressful use context, all to assure high quality CPR and more survivors.