Using monocular images to estimate interaction forces during minimally invasive surgery

The lack of haptic feedback during minimally invasive surgery can cause significant tissue damage and increase morbidity. Estimating the applied force from endoscopic images is a promising approach, especially using binocular images. However, many existing operation rooms are only equipped with monocular endoscopes, making force estimation more problematic. In this paper a new method for estimating the applied force from monocular endoscope images is proposed. The main contribution is the concept of virtual template that enables modeling of surface deformation without the knowledge of the undeformed shape. Results of the in vitro experiment with the lamb liver support the practicality and effectiveness of the proposed method.