Petros Giataganas

Cooperative in situ microscopic scanning and simultaneous tissue surface reconstruction using a compliant robotic manipulator

Recent technological advances in surgery have permitted cellular and molecular imaging to be carried out intra-operatively. Although optical biopsy techniques such as probe-based confocal laser endomicroscopy (pCLE) have enabled real-time diagnosis and tissue characterisation in vivo, the flexibility of the probe introduces significant challenges under manual control. Examination of large tissue areas is particularly challenging due to micron-scale resolution of the probe and the need for maintaining consistent probe orientation and force contact with the tissue to avoid cellular deformation or damage. The use of a robotic manipulator to perform surface scanning automatically introduces great benefits in terms of positioning repeatability and accuracy. However, pre-programming of such complex task is not realistic due to patient-specific anatomy and constant changes in tissue morphology during the operation. To overcome this problem, a cooperative, in situ microscopic scanning and simultaneous tissue surface reconstruction technique is proposed. The system provides a hands-on, learning-based framework for optimal trajectory coverage from surgeon-demonstrated motions intraoperatively. The position and force information acquired during the scanning are also used to simultaneously reconstruct the surface morphology and combined with the pCLE images to generate a 3D functional map of the tissue.

Force adaptive robotically assisted endomicroscopy for intraoperative tumour identification

PurposeFor 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

Color reflectance fiber bundle endomicroscopy without back- reflections

\hbox {Vinci}^\circledR

Implicit Active Constraints for robot-assisted arthroscopy

Vinci®, lack haptic feedback, making it difficult to maintain optimum tissue contact when these probes are deployed in vivo.MethodsThis 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.ResultsThe 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.ConclusionsThe device can improve the performance of large area mosaicking over complex 3D surfaces with improved handling and intraoperative control.

Autonomous eFAST ultrasound scanning by a robotic manipulator using learning from demonstrations

Robot-assisted minimally invasive surgery can benefit from the automation of common, repetitive or well-defined but ergonomically difficult tasks. One such task is the scanning of a pick-up endomicroscopy probe over a complex, undulating tissue surface to enhance the effective field-of-view through video mosaicing. In this paper, the da Vinci® surgical robot, through the dVRK framework, is used for autonomous scanning and 2D mosaicing over a user-defined region of interest. To achieve the level of precision required for high quality mosaic generation, which relies on sufficient overlap between consecutive image frames, visual servoing is performed using a combination of a tracking marker attached to the probe and the endomicroscopy images themselves. The resulting sub-millimetre accuracy of the probe motion allows for the generation of large mosaics with minimal intervention from the surgeon. Images are streamed from the endomicroscope and overlaid live onto the surgeons view, while 2D mosaics are generated in real-time, and fused into a 3D stereo reconstruction of the surgical scene, thus providing intuitive visualisation and fusion of the multi-scale images. The system therefore offers significant potential to enhance surgical procedures, by providing the operator with cellular-scale information over a larger area than could typically be achieved by manual scanning.

Effective Manipulation in Confined Spaces of Highly Articulated Robotic Instruments for Single Access Surgery

Abstract. Coherent fiber imaging bundles can be used as passive probes for reflectance-mode endomicroscopy providing that the back-reflections from the fiber ends are efficiently rejected. We describe an approach specific to widefield endomicroscopy in which light is injected into a leached fiber bundle near the distal end, thereby avoiding reflections from the proximal face. We use this method to demonstrate the color widefield reflectance endomicroscopy of ex vivo animal tissue.

Development of a large area scanner for intraoperative breast 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.

A Single-Port Robotic System for Transanal Microsurgery—Design and Validation

This paper presents an Implicit Active Constraints control framework for robot-assisted minimally invasive surgery. It extends on current frameworks by prescribing the external constraints implicitly from the operator motion, forgoing the need for pre-operative imaging; the constraints are defined in situ so as to avoid the use of invasive fiducial markers. A hands-on cooperatively-controlled robotic platform, comprising of a surgical instrument and a compliant manipulator, has been designed for an arthroscopic procedure. The surgical platform is capable of constraining the pose of the instrument so as to ensure it passes through the incision point and does not cause trauma to the surrounding tissue. A flexible arthroscopic instrument is designed and its use is investigated to enlarge reachable and dexterous workspace, increasing the accessibility to the target anatomy. The behaviour of the flexible instrument is analysed. A detailed performance analysis is conducted on a group of subjects for validating the control framework, simulating a minimally invasive arthroscopic procedure. Results demonstrate a statistically significant enhancement in the control ergonomics as well as the accuracy and safety of the procedure.