Development of a large area scanner for intraoperative breast endomicroscopy

Recent work on probe-based confocal endomicroscopy has demonstrated its potential role for real-time assessment of tumour margins during breast conserving surgery. However, endomicroscope probes tend to have a very small field-of-view, making surveillance of large areas of tissue difficult, and limiting practical clinical deployment. In this paper, a new robotic device for controlled, large area scanning based on a fibre bundle endomicroscope probe is proposed. The prototype uses a 2-DOF mechanism (−90 to +90 degrees bending on one axis, 360 degrees of rotation on a second axis) as well as a passive linear structure to conform to undulating surfaces. Both axes are driven by brushless DC servo motors with computer control, thus facilitating large field-of-view mosaicing. Experimental results have shown good repeatability and low hysteresis of the device, which is able to scan different surface trajectories (e.g. a spiral pattern over a hemi-spherical surface) with consistent tissue contact. Ex vivo human breast tissue results are demonstrated, illustrating a viable scanning approach for breast endomicroscopy.