A miniaturised robotic probe for real-time intraoperative fusion of ultrasound and endomicroscopy

Transanal Endoscopic Microsurgery (TEM) is a minimally invasive oncological resection procedure that utilises a natural orifice approach rather than the traditional abdominal or open approach. However, TEM has a significant recurrence rate due to incomplete excisions, which can possibly be attributed to the absence of intraoperative image guidance. The use of real-time histological data could allow the surgeons to assess the surgical margins intraoperatively and adjust the procedure accordingly. This paper presents the integration of endomicroscopy and ultrasound imaging through a robotically actuated instrument. Endomicroscopy can provide high resolution images at a surface level while ultrasound provides depth resolved information at a macroscopic level. Endomicroscopy scanning is achieved with a novel scanning approach featuring a passive force adaptive mechanism. The instrument is manipulated across the surgical workspace through an articulated flexible shaft. This results in the ability to perform large area mosaics coupled with ultrasound scanning. In addition, the use of endoscopic tracking is demonstrated, allowing three-dimensional reconstruction of the ultrasound data displayed onto the endoscopic view. An ex vivo study on porcine colon tissue has been performed, demonstrating the clinical applicability of the instrument.