The Centre has a long history of developing new techniques for medical imaging (particularly in magnetic resonance imaging), transforming them from a primarily diagnostic modality into an interventional and therapeutic platform. This is facilitated by the Centre's strong engineering background in practical imaging and image analysis platform development, as well as advances in minimal access and robotic assisted surgery. Hamlyn has a strong tradition in pursuing basic sciences and theoretical research, with a clear focus on clinical translation.

In response to the current paradigm shift and clinical demand in bringing cellular and molecular imaging modalities to an in vivo – in situ setting during surgical intervention, our recent research has also been focussed on novel biophotonics platforms that can be used for real-time tissue characterisation, functional assessment, and intraoperative guidance during minimally invasive surgery. This includes, for example, SMART confocal laser endomicroscopy, time-resolved fluorescence spectroscopy and flexible FLIM catheters.


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  • Journal article
    Giannarou S, Ye M, Gras G, Leibrandt K, Marcus HJ, Yang GZet al., 2016,

    Vision-based deformation recovery for intraoperative force estimation of tool–tissue interaction for neurosurgery

    , International Journal of Computer Assisted Radiology and Surgery, Vol: 11, Pages: 929-936, ISSN: 1861-6410

    Purpose In microsurgery, accurate recovery of the deformationof the surgical environment is important for mitigatingthe risk of inadvertent tissue damage and avoiding instrumentmaneuvers that may cause injury. The analysis of intraoperativemicroscopic data can allow the estimation of tissuedeformation and provide to the surgeon useful feedbackon the instrument forces exerted on the tissue. In practice,vision-based recovery of tissue deformation during tool–tissue interaction can be challenging due to tissue elasticityand unpredictable motion.Methods The aim of this work is to propose an approachfor deformation recovery based on quasi-dense 3D stereoreconstruction. The proposed framework incorporates a newstereo correspondence method for estimating the underlying3D structure. Probabilistic tracking and surface mapping areused to estimate 3D point correspondences across time andrecover localized tissue deformations in the surgical site.Results We demonstrate the application of this method toestimating forces exerted on tissue surfaces. A clinically relevantexperimental setup was used to validate the proposedframework on phantom data. The quantitative and qualitativeperformance evaluation results show that the proposed3D stereo reconstruction and deformation recovery methodsachieve submillimeter accuracy. The force–displacementmodel also provides accurate estimates of the exerted forces.Conclusions A novel approach for tissue deformationrecovery has been proposed based on reliable quasi-densestereo correspondences. The proposed framework does notrely on additional equipment, allowing seamless integration with the existing surgical workflow. The performanceevaluation analysis shows the potential clinical value of thetechnique.

  • Journal article
    Zhao L, Giannarou S, Lee S, Yang GZet al., 2016,

    SCEM+: real-time robust simultaneous catheter and environment modeling for endovascular navigation

    , IEEE Robotics and Automation Letters, Vol: 1, Pages: 961-968, ISSN: 2377-3766

    Endovascular procedures are characterised by significant challenges mainly due to the complexity in catheter control and navigation. Real-time recovery of the 3-D structure of the vasculature is necessary to visualise the interaction between the catheter and its surrounding environment to facilitate catheter manipulations. State-of-the-art intraoperative vessel reconstruction approaches are increasingly relying on nonionising imaging techniques such as optical coherence tomography (OCT) and intravascular ultrasound (IVUS). To enable accurate recovery of vessel structures and to deal with sensing errors and abrupt catheter motions, this letter presents a robust and real-time vessel reconstruction scheme for endovascular navigation based on IVUS and electromagnetic (EM) tracking. It is formulated as a nonlinear optimisation problem, which considers the uncertainty in both the IVUS contour and the EM pose, as well as vessel morphology provided by preoperative data. Detailed phantom validation is performed and the results demonstrate the potential clinical value of the technique.

  • Conference paper
    Zhou X, Ernst S, Lee S, 2016,

    Path planning for robot-enhanced cardiac radiofrequency catheter ablation

    , IEEE International Conference on Robotics and Automation, Publisher: IEEE

    Radiofrequency Catheter Ablation (RFCA) is aprocedure used to treat cardiac arrhythmias by burning atregions of the endocardial walls to prevent the abnormalelectrical circuits causing the problem. Patients with AdultCongenital Heart Disease (ACHD) who have undergone surgicaltreatments suffer scarring within the heart that can lead to ab-normal cardiac rhythms. However, poor intraoperative cardiacgeometry recovery and incomplete Electrophysiological (EP)mapping due to limited available procedure time and complexanatomy have resulted in difficulty to detect the regions toablate and hence relatively high recurrence rates. In this paper,we present a catheter path planning algorithm to optimisecardiac EP mapping. Firstly, the optimal mapping positions aredetermined by curvature and distance weighted Quadric ErrorMetric Simplification (QEMS) to maximally recover the cardiacchamber geometry and EP mapping. Secondly, an efficient pathis designed that moves along a predetermined axis for a roboticcatheter to pass through and collect EP data at these positions.Validation is performed on retrospectively collected CARTOdata from ACHD patients.

  • Journal article
    Kassahun Y, Yu B, Tibebu AT, Stoyanov D, Giannarou S, Metzen JH, Poorten EVet al., 2016,

    Surgical robotics beyond enhanced dexterity instrumentation: a survey of machine learning techniques and their role in intelligent and autonomous surgical actions (vol 11, pg 553, 2016)

    , International Journal of Computer Assisted Radiology and Surgery, Vol: 11, Pages: 847-847, ISSN: 1861-6410
  • Conference paper
    Constantinescu M, Lee S, Ernst S, Yang GZet al., 2016,

    Traversed Graph Representation for Sparse Encoding of Macro-Reentrant Tachycardia

    , Statistical Atlases and Computational Models of the Heart. Imaging and Modelling Challenges, Publisher: Springer, Pages: 40-50, ISSN: 0302-9743

    Macro-reentrant atrial and ventricular tachycardias originatefrom additional circuits in which the activation of the cardiac chambersfollows a high-frequency rotating pattern. The macro-reentrant circuitcan be interrupted by targeted radiofrequency energy delivery with alinear lesion transecting the pathway. The choice of the optimal ablationsite is determined by the operator’s experience, thus limiting the proceduresuccess, increasing its duration and also unnecessarily extendingthe ablated tissue area in the case of incorrect ablation target estimation.In this paper, an algorithm for automatic intraoperative detection of thetachycardia reentry path is proposed by modelling the propagation as agraph traverse problem. Moreover, the optimal ablation point where thepath should be transected is computed. Finally, the proposed methodis applied to sparse electroanatomical data to demonstrate its use whenundersampled mapping occurs. Thirteen electroanatomical maps of rightventricle and right and left atrium tachycardias from patients treatedfor congenital heart disease were analysed retrospectively in this study,with prediction accuracy tested against the recorded ablation sites andarrhythmia termination points.

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