The abstract says:
Accurate estimation and tracking of dynamic tissue deformation is important to motion compensation, intra-operative surgical guidance and navigation in minimally invasive surgery. Current approaches to tissue deformation tracking are generally based on machine vision techniques for natural scenes which are not well suited to MIS because tissue deformation cannot be easily modeled by using ad hoc representations. Such techniques do not deal well with inter-reflection changes and may be susceptible to instrument occlusion. The purpose of this paper is to present an online learning based feature tracking method suitable for in vivo applications.
In other words, they are augmenting a live beating heart, muhahaha!
Soft Tissue Tracking for Minimally Invasive Surgery Learning Local Deformation Online. Peter Mountney and Guang-Zhong Yang