Treating Out-of-Hospital Cardiac Arrest (OHCA): Automatic Chest Compression Device for Adaptive Cardiopulmonary Resuscitation (CPR)

 
By: Mirrah Almira - CMI Fellow  

Introduction: The fact that patients vary in anatomy and underlying pathology makes a "one-size-fits-all" CPR technology insufficient for treatment of OHCA. Aiming to provide a better emergency treatment for cardiac arrest, a team of Pitt engineers and doctors has created an automatic chest compression device to fulfill the need of an adaptive CPR technology.

[Pittsburgh, February 3, 2015] Whenever a patient is having a cardiac arrest (OHCA), his/her heart acts like a "broken pump" that is incapable of pumping blood throughout the body. The treatment for OHCA involves cardiopulmonary resuscitation (CPR). This technique consists of rescue breaths and chest compressions to keep oxygenated blood circulating inside the body and to maintain the function of vital organs. Since the "broken pump" is not similar from one to another, each OHCA case needs to be treated differently. The CPR should be adjusted accordingly to each patient's physiologic condition.

Treatments that are presently available, such as human-performed CPR and the current automatic CPR devices, do not account for patient variability. Human-performed CPR is based on The American Heart Association recommendation, which calls for a chest compression rate of 100 compressions per minute at a depth of 2 inches. This is fixed for all patients and does not account for patient size and physiologic variability. The same "one-size-fits-all" depth and rate are also used in the current automatic CPR devices, such as Thumper(R) and AutoPulse(R). These devices do not consider differences in anatomy and physiology of the patient, e.g. chest size, and do not receive physiologic input that measures the effectiveness of the CPR itself.

In order to fulfill the need of an adaptive CPR technology, a team of researchers at the University of Pittsburgh has produced an automatic chest compression device that can provide a more personalized treatment. The device is able to adjust its compression rate and depth in response to patient physiologic feedback. The device would then monitor feedback such as blood pressure (central arterial pressure) and electrocardiogram characteristics to analyze the effectiveness of a certain depth or rate and then subsequently change that depth or rate until it produces an optimum physiologic response. This mechanism enables the smart automatic device to give an effective, possibly superior CPR compared to a fixed parameter device.

This novel automatic compression device is the result of collaborative work between the University of Pittsburgh Swanson School of Engineering and The School of Medicine: 
 

 
The $19,000 grant from CMI during the period of 2013-2014, has helped the automatic chest compression device team in achieving their targets. The team has built the prototype of the device, conducted cardiac arrest swine experiments, and validated the proof of concept of adaptive CPR. The team has filed a patent through the University of Pittsburgh Office of Technology Management and has explored licensing agreements with current manufacturers of mechanical chest compression devices.

In the future, the team plans to continue its research and develop algorithms that further improve the quality and outcomes of CPR, also actively maintain communication with the manufacturers of current chest compression devices. The team hopes to make headway towards a technology license with a manufacturer of medical devices. (MA)