Haptic Perception of Distance-To-Break for Compliant Tissues in a Surgical Simulator

In minimally invasive surgery (MIS), it is critical to have the ability to accurately interpret haptic information and apply appropriate force magnitudes onto soft tissue in order to minimize tissue trauma. The surgeon’s administration of force onto tissue reveals useful perceptual information which guides further haptic interaction making the force perception in MIS a dynamic process. It has been hypothesized that the compliant nature of soft tissue during force application provides biomechanical information denoting tissue failure. Specifically, the relationship between applied force and material deformation rate specifies the distance remaining until the tissue will fail, which is termed distance-to-break (DTB). Two experiments explored sensitivity to DTB; one with an exploratory task and the other using a unidirectional task. Findings revealed that observers could reliably perceive DTB in simulated biological tissues in the exploratory task but they were unable to perform the unidirectional task. It was also found that the perception of DTB can be improved through feedback training. Implications for optimizing training in MIS simulators are discussed.