STD CPR by itself is inherently inefficient, in large part due to the lack of mechanical forces to draw blood into the heart during the chest wall recoil phase in order to refill the emptied chambers of the heart after each chest compression. Moreover, the coronary perfusion pressure is only marginally adequate as the pressure gradient between the aorta, the right atrium and left ventricle is far from optimal. When these inherent inefficiencies are combined with the multiple common errors associated with CPR performance (e.g. hyperventilation, incomplete chest wall depth and recoil) and the element of physical fatigue documented by even the fit and well-trained professional providers of CPR, it is clearly time for an industrial revolution in resuscitation and a better mechanical means to perform automated CPR. Based upon a combination of newly discovered multiple mechanisms to enhance circulation during CPR and the need to reduce human errors intrinsic to the performance of manual closed chest CPR, the goal of this SBIR phase 1 application is to develop a novel automated CPR device to further improve blood flow during cardiac arrest. The new automated device combines the concept of negative intrathoracic pressure (ITP) to enhance cardiac preload and lower resistance to brain blood flow by lowering intracranial pressure with that of providing intermittent, yet moderate, positive intrathoracic compression-phase pressures using oxygen insufflation to additionally enhance forward blood flow while maintaining oxygenation. The innovation of the new device lies in its design to optimize circulation of blood to the brain and other vital organs throughout the entire CPR cycle. Two core technologies will be combined in this 5-cycle automated CPR technology. They include: 1) a sternal active compression-decompression device to provide continuous chest compressions and full chest recoil, and 2) an electronic airway valve to both lower ITP during the chest decompression phase and provide passive oxygen insufflation after every other decompression to optimize circulation and provide ongoing hands-free ventilation. These two core technologies will be CPR-cycle synchronized to enhance cardiac preload, cardiac output, continuous blood flow to the brain, and oxygen delivery with a single automated device that does not rely on the quality of CPR provided by the caregiver.
The specific aims of this research proposal are to: 1) Design and build a prototype non- invasive automated CPR device for the treatment of cardiac arrest to provide optimal continuous circulation to the brain and other vital organs;2) Demonstrate that use of the novel CPR device will significantly improve acute hemodynamics, vital organ blood flow, and 24-hour neurologically-intact survival when compared with STD CPR plus the ITD in a porcine model of cardiac arrest. This unique combination of non-invasive physiologically-based mechanisms has the potential to provide normal levels of circulation and ventilation during cardiac arrest which can significantly improve long-term neurologically-intact survival rates. If successful, this invention will result in saving >10,000 more Americans each year from out of hospital cardiac arrest and a similar number of in-hospital survivors based upon the superior blood flow and the ability to perform prolonged CPR with normal physiology.
Based upon a combination of multiple newly discovered mechanisms to enhance circulation during CPR and the need to reduce human errors intrinsic to the performance of manual closed chest CPR, the goal of this SBIR phase 1 application is to develop a novel automated CPR device to further improve blood flow during cardiac arrest. Two core technologies will be combined to produce a 5- cycle automated CPR technology. They include: 1) a sternal active compression-decompression device to provide continuous chest compressions and full chest recoil, and 2) an electronic regulated airway pressure valve to both lower ITP during the chest decompression phase and provide passive oxygen insufflation after every other decompression to optimize circulation and provide ongoing hands-free ventilation. These two core technologies will be CPR-cycle synchronized to enhance cardiac preload, cardiac output, continuous blood flow to the brain, and oxygen delivery with a single automated device that does not rely on the quality of CPR provided by the caregiver. This technology is needed because high quality STD CPR provides less than 20% of normal blood flow to the heart and little more to the brain. Even in the most efficient emergency medical systems, less than 20% of all patients with an out-of-hospital cardiac arrest are discharged from the hospital with intact neurological function. Strikingly, the average national survivals to hospital discharge after out-of- hospital cardiac arrest has remained less than 5% for decades. This complex disease state remains the nation's #1 killer, claiming more than 1000 lives outside the hospital and 1000 lives inside the hospital each day in the United States alone. Improved circulation to the brain and other vital organs during CPR, especially when combined in an overall systems-based approach to pre and post- resuscitation care, has the potential to significantly reduce morbidity and mortality from cardiac arrest.
