Guidance of a steerable cannula robot in soft tissue using preoperative imaging and conoscopic surface contour sensing

Intraoperative surface contour sensing can enable the registration of high-resolution three-dimensional preoperative images for precise guidance of surgical robots. This is particularly useful for guiding steerable needles in soft tissues. In this paper we combine a new minimally invasive surface scanning technique based on conoscopic holography with a steerable active cannula robot. We experimentally demonstrate cannula tip placement to multiple physical points inside phantom tissue, which correspond to points specified in preoperative images - the input an eventual clinical system would obtain from the physician. While the image-guided steerable system we propose is broadly applicable to many kinds of surgery, one particular application of interest is in ablating large liver tumors, where it is beneficial for the ablator to be repositioned to multiple locations without being withdrawn from the organ.