A chest compression feedback device is a tool that is used in the monitoring the quality of cardiopulmonary resuscitation (CPR).
The quality of CPR regarding the depth, rate, and chest recoil are monitored. The device also provides corrective feedback to the rescuers
CPR is simply the lifesaving technique that is done when a person stops breathing and it keeps both oxygen and blood to flow through the body.
In conclusion, the chest compression feedback devices monitor "CPR quality regarding chest recoil, rate and depth".