The ResQPOD is an Impedance Threshold Device, or ITD, that significantly increases circulation during CPR for patients in cardiac arrest. The non-invasive, single-use device prevents unnecessary air from entering the chest during CPR, creating a negative pressure vacuum as the chest recoils. The enhanced vacuum refills the heart after each chest compression, increasing blood flow to the heart. The increased preload to the heart helps make compressions more effective and increases the chances of a successful defibrillation and return of spontaneous circulation.