Force adaptive robotically assisted endomicroscopy for intraoperative tumour identification

For effective tumour margin definition for cancer surgery, there is an increasing demand for the development of real-time intraoperative tissue biopsy techniques. Recent advances in miniaturized biophotonics probes have permitted the development of endomicroscopy techniques that are clinically attractive. With these approaches, cellular-level imaging can be achieved through millimetre-scale flexible probes and be performed in real-time, in vivo and in situ. Due to the limited field of view and flexibility of these probes, however, large area tissue coverage for acquiring histology-like images over complex three-dimensional surfaces is challenging. This is particularly the case because current surgical robots, such as the Da Vinci ®, lack haptic feedback, making it difficult to maintain optimum tissue contact when these probes are deployed in vivo.

This paper proposes a simple force-controlled pick-up probe that can be integrated with the Da Vinci instruments for intraoperative endomicroscopy imaging. The device uses a new low-friction air bearing with adaptive axial force control to maintain constant contact between the tissue and the imaging probe, facilitating microscopy scans over complex surfaces. Detailed ex vivo user experiments have been conducted to demonstrate the effectiveness of the technique.

The adaptive probe mount could achieve consistent low-magnitude probe-sample contact forces compared with a rigid mount. In the user study, the adaptive probe combined with a high frame rate endomicroscopy system allowed larger mosaics to be generated over curved surfaces.

The device can improve the performance of large area mosaicking over complex 3D surfaces with improved handling and intraoperative control.