Given the difficulty of performing consistent CPR compressions, technology has turned to automation.
There are two types of automated compressors available. Pneumatically driven piston compressors were first introduced into clinical practice in the 90s. These devices drive a piston to compress the heart against the backbone in the same manner as manual CPR.
This device uses pneumatic power to drive a piston that is manually set by the rescuer to deliver a fixed depth of compression. The device can be set to comply with the Guidelines 2010, and there is an optional hands-free ventilation capability.
It uses a small backboard under the patient's shoulders, then a U-shaped pump snaps on over the chest. A push of the button, and a pump lowers down onto the patient's chest, and begins hard, fast compressions.
It pumps the perfect pressure, at the perfect interval, and it will go forever: sideways through a stairwell, standing up in an elevator, upside down in a bumpy ambulance, it doesn't matter. No human hands could match that.
Studies show that the longer and more perfect the CPR, the better chance you'll survive.