A novel tumor localization method using haptic palpation based on soft tissue probing data

Current surgical tele-manipulators do not provide explicit haptic feedback during soft tissue palpation. Haptic information could improve the clinical outcomes significantly and help to detect hard inclusions within soft-tissue organs indicating potential abnormalities. However, system instability is often caught by direct force feedback. In this paper, a new approach to intra-operative tumor localization is introduced. A virtual-environment tissue model is created based on the reconstructed surface of a soft-tissue organ using a Kinect depth sensor and the organ's stiffness distribution acquired during rolling indentation measurements. Palpation applied to this tissue model is haptically fed back to the user. In contrast to previous work, our method avoids the control issues inherent to systems that provide direct force feedback. We demonstrate the feasibility of this method by evaluating the performance of our tumor localization method on a soft tissue phantom containing buried stiff nodules. Results show that participants can identify the embedded tumors; the proposed method performed nearly as well as manual palpation.