Understanding soft tissue behavior for microlaparoscopic surface scan

This paper presents an approach for understanding the soft tissue behavior in surface contact with a hard object scanning the tissue. The application domain is confocal microlaparoscope imaging, mostly used for imaging the outer surface of the organs in the abdominal cavity. The probe (optic-head) is swept over the tissue to collect sequential images to obtain a large field of view with mosaicing. The problem we address is that the tissue also moves with the probe due to its softness; therefore the resulting mosaic is not in the same shape and dimension as traversed by the probe. Our approach inspires from the finger slip studies and adapts the idea of load-and-slip that explains the movement of the finger when dragged on a hard surface. We propose the concept of loading-distance and perform measurements with in total 84 experiments on beef liver and chicken breast tissues. Our results indicate that the loading-distance can be measured prior to a scan and be used during the scan in order to compensate the movement of the probe. In this way we can have an image-mosaic of the tissue surface in a desired shape.