Improved Cardiopulmonary Resucitation Device

Cardio-pulmonary resuscitation (CPR) plays an important role in the outcome of sudden cardiac arrest, where survival rates continue to be very low, about 5%. CPR has evolved significantly from the days when it was standard practice to flap the arms of victimes, or roll their bodies back and forth over a wooden barrel. Today, many people know the standard technique of giving chest compressions. Others may know about enhancement devices (e.g., ResQPOD) that use a basic mechanics concept of creating negative thoracic pressure during the decompression phase of CPR. This is done by adding inflow resistance to the patient's airway, such that a vacuum is created at each chest decompression. The vacuum pulls blood into the thorax, in effect “priming the pump” with more blood, which is then ejected in the next compression phase. We present an enhancement to the above proven concept of airway restriction during CPR by further adding total airway occlusion to the inflow and outflow of air at appropriate times, by use of a CPR enhancement device (CED). With a face mask and electronic airway valve, maximal vacuum and positive pressures are created in the thorax to enhance blood circulation during cardiac arrest. A CPR cycle is proposed with five phases including two for free air exchange, without the need to interrupt compressions, and adhering to AHA guidelines of 100 compressions per minute. To test the CED, a human cardiopulmonary model is described that allows blood pressure changes to be measured with the various forms of CPR, new and conventional. Preliminary data from testing both CED and standard CPR on the thorax model were found in terms of mean, systolic and diastolic pressure. T-tests evaluated statistical significance. During normal CPR, average systolic pressure was found to be $35.3±0.6$ mmHg. When the CED was applied, the average systolic pressure was found to be $62.9±4.5$ mmHg $(p=0.0002)$⁠. Average diastolic pressure for normal CPR was found to be $30.4±0.4$ mmHg while that of the CED was observed to be $28.6±1.2$ mmHg $(p=0.095,NS)$⁠. The MAP calculated from standard CPR resulted in an average of $32.0±0.4$ mmHg, while that using the CED was $40±2.1$ mmHg, $(p=0.002)$⁠. Based on this preliminary testing and data analysis, the CED shows a significant improvement in systolic and mean arterial pressure in comparison to standard CPR. This supports the CED five phase method that provides positive pressure and vacuum in the cardiopulmonary system during resuscitation. Future work will compare the CED to other CPR enhancement devices.