PDF Is patent applicationCardiac retractors include a rod and a foldable blade that can be introduced using minimally invasive access ports such that provided by an intra-thoracic cavity cannula. The rod can be integral to the blade or may be releasably attached in situ. The devices may be sized and configured to reside in situ proximate the mitral valve site at a left atria to splint open (lift a roof of) the mitral valve in response to robotic controlled direction of a surgeon for a mitral valve repair during a closed chest minimally invasive cardiac surgery