  Robot-assisted minimally invasive surgery has shown to improve patient
outcomes, as well as reduce complications and recovery time for several
clinical applications. While increasingly configurable robotic arms can
maximize reach and avoid collisions in cluttered environments, positioning them
appropriately during surgery is complicated because safety regulations prevent
automatic driving. We propose a head-mounted display (HMD) based augmented
reality (AR) system designed to guide optimal surgical arm set up. The staff
equipped with HMD aligns the robot with its planned virtual counterpart. In
this user-centric setting, the main challenge is the perspective ambiguities
hindering such collaborative robotic solution. To overcome this challenge, we
introduce a novel registration concept for intuitive alignment of AR content to
its physical counterpart by providing a multi-view AR experience via
reflective-AR displays that simultaneously show the augmentations from multiple
viewpoints. Using this system, users can visualize different perspectives while
actively adjusting the pose to determine the registration transformation that
most closely superimposes the virtual onto the real. The experimental results
demonstrate improvement in the interactive alignment of a virtual and real
robot when using a reflective-AR display. We also present measurements from
configuring a robotic manipulator in a simulated trocar placement surgery using
the AR guidance methodology.
