Laser-Induced Fluorescence and Reflected White Light Imaging for Robot-Assisted MIS

This paper presents an articulated robotic-controlled device to facilitate large-area in vivo tissue imaging and characterization through the integration of miniaturized reflected white light and fluorescence intensity imaging for minimally invasive surgery (MIS). The device is composed of a long, rigid shaft with a robotically controlled distal tip featuring three degrees of in-plane articulation and one degree of rotational freedom. The constraints imposed by the articulated section, coupled with the small footprint available in MIS devices, require a novel optical configuration to ensure effective target illumination and image acquisition. A tunable coherent supercontinuum laser source is used to provide sequential white light and fluorescence illumination through a multimode fiber (200 mum diameter), and the reflected images are transmitted to an image acquisition system using a 10 000 pixel flexible fiber image guide (590 mum diameter). By using controlled joint actuation to trace overlapping trajectories, the device allows effective imaging of a larger field of view than a traditional dual-mode laparoscope. A first-generation prototype of the device and its initial phantom and ex vivo tissue characterization results are described. The results demonstrate the potential of the device to be used as a new platform for in vivo tissue characterization and navigation for MIS.