Tumor Depth and Size Perception Using a Pneumatic Tactile Display in Laparoscopic Surgery

Tumor location, depth, and size are essential information for tumor resection surgery. In open surgery, surgeons can obtain information by palpating the tissue with their fingers. In minimally invasive surgery, where the natural sense of touch is restricted, surgeons can rely on haptic information provided by haptic devices to determine the tumor characteristics. Tactile feedback is a promising representation modality for providing haptic information intuitively to surgeons during tissue palpation. In this paper, we propose a palpation strategy using tactile feedback to determine the tumor depth and size. For the palpation strategy, the tumor depth was determined by detecting the presence of the tumor at a given indentation depth of the sensor. Tumor size may be obtained by localizing the tumor edges. Fundamental experiments were conducted to investigate the use of contact force components in determining tumor features using the proposed strategy. The results indicated that the normal force is more useful in estimating the indentation depth, and the shear force is highly effective in detecting tumor regions and edges. Users’ ability to characterize the tumor using tactile feedback from our developed tactile display was demonstrated through tissue palpation tasks. Participants who received both normal force and shear force feedback could identify the depth and size of the embedded tumor with 66 % and 65 % accuracy, respectively. These results suggest that tactile displays that provide normal and shear force feedback can be successfully used for tumor characterization.