Reading their website (http://www.carmatsa.com/index.php?option=com_flexicontent&vi...), as near as I can tell, they're basically claiming to be "closest yet" to a real heart, including "auto-regulation", which I think means they're saying it can beat faster or slower as you need more or less bloodflow.

The scariest thing is that they also boast a significant increase in battery life ... to 12 hours. Jesus, I get angry when my cell phone dies after 12 hours.