Imperial College London

Dr George Mylonas

Faculty of MedicineDepartment of Surgery & Cancer

Lecturer in Robotics and Technology in Cancer
 
 
 
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Contact

 

+44 (0)20 3312 5145george.mylonas Website

 
 
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Location

 

Room 5Paterson WingSt Mary's Campus

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Summary

 

Publications

Publication Type
Year
to

87 results found

Saracino A, Oude-Vrielink TJC, Menciassi A, Sinibaldi E, Mylonas GPet al., 2020, Haptic Intracorporeal Palpation Using a Cable-Driven Parallel Robot: A User Study, IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, Vol: 67, Pages: 3452-3463, ISSN: 0018-9294

Journal article

Arezzo A, Francis N, Mintz Y, Adamina M, Antoniou SA, Bouvy N, Copaescu C, de Manzini N, Di Lorenzo N, Morales-Conde S, Mueller-Stich BP, Nickel F, Popa D, Tait D, Thomas C, Nimmo S, Paraskevis D, Pietrabissa Aet al., 2020, EAES Recommendations for Recovery Plan in Minimally Invasive Surgery Amid COVID-19 Pandemic, SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES, Vol: 35, Pages: 1-17, ISSN: 0930-2794

Journal article

Avery J, Shulakova D, Runciman M, Mylonas GP, Darzi Aet al., 2020, Tactile sensor for minimally invasive surgery using Electrical Impedance Tomography, IEEE Transactions on Medical Robotics and Bionics, Vol: 2, Pages: 561-564, ISSN: 2576-3202

Whilst offering numerous benefits to patients, minimally invasive surgery (MIS) has a disadvantage in the loss of tactile feedback to the surgeon, traditionally offering valuable qualitative tissue assessment, such as tumour identification and localisation. Tactile sensors aim to overcome this loss of sensation by detecting tissue characteristics such as stiffness, composition and temperature. Tactile sensors have previously been incorporated into MIS robotic end effectors, which require lengthy scanning procedures due to localised sensitivity. Distributed tactile sensors, or “artificial skin” offer a map of tissue properties in a single instance but are often not suitable for MIS applications due to limited biocompatibility or large collapsed volumes. We propose a deployable, soft, tactile sensor with a deformable saline chamber and integrated Electrical Impedance Tomography (EIT) electrodes. During contact with tissue, the saline is displaced from the chamber and the lesion size and stiffness can be inferred from the resultant impedance changes. Through optimisation of the EIT measurement protocol and hardware the sensor was capable of localising the centre of mass of palpation targets within 1.5 mm in simulation and 2.3–4.6mm in phantom experiments. Reconstructed image metrics differentiated target objects from 8–30 mm.

Journal article

Cursi F, Mylonas GP, Kormushev P, 2020, Adaptive kinematic modelling for multiobjective control of a redundant surgical robotic tool, Robotics, Vol: 9, Pages: 68-68, ISSN: 2218-6581

Accurate kinematic models are essential for effective control of surgical robots. For tendon driven robots, which are common for minimally invasive surgery, the high nonlinearities in the transmission make modelling complex. Machine learning techniques are a preferred approach to tackle this problem. However, surgical environments are rarely structured, due to organs being very soft and deformable, and unpredictable, for instance, because of fluids in the system, wear and break of the tendons that lead to changes of the system’s behaviour. Therefore, the model needs to quickly adapt. In this work, we propose a method to learn the kinematic model of a redundant surgical robot and control it to perform surgical tasks both autonomously and in teleoperation. The approach employs Feedforward Artificial Neural Networks (ANN) for building the kinematic model of the robot offline, and an online adaptive strategy in order to allow the system to conform to the changing environment. To prove the capabilities of the method, a comparison with a simple feedback controller for autonomous tracking is carried out. Simulation results show that the proposed method is capable of achieving very small tracking errors, even when unpredicted changes in the system occur, such as broken joints. The method proved effective also in guaranteeing accurate tracking in teleoperation.

Journal article

Runciman M, Darzi A, Mylonas GP, 2020, Soft robotics in minimally invasive surgery (Part 2), Galvanotechnik, Vol: 111, Pages: 1236-1237, ISSN: 0016-4232

Journal article

Kinross JM, Mason SE, Mylonas G, Darzi Aet al., 2020, Next-generation robotics in gastrointestinal surgery, Nature Reviews Gastroenterology and Hepatology, Vol: 17, Pages: 430-440, ISSN: 1759-5045

The global numbers of robotic gastrointestinal surgeries are increasing. However, the evidence base for robotic gastrointestinal surgery does not yet support its widespread adoption or justify its cost. The reasons for its continued popularity are complex, but a notable driver is the push for innovation — robotic surgery is seen as a compelling solution for delivering on the promise of minimally invasive precision surgery — and a changing commercial landscape delivers the promise of increased affordability. Novel systems will leverage the robot as a data-driven platform, integrating advances in imaging, artificial intelligence and machine learning for decision support. However, if this vision is to be realized, lessons must be heeded from current clinical trials and translational strategies, which have failed to demonstrate patient benefit. In this Perspective, we critically appraise current research to define the principles on which the next generation of gastrointestinal robotics trials should be based. We also discuss the emerging commercial landscape and define existing and new technologies.

Journal article

Zhao M, Oude Vrielink TJC, Kogkas A, Runciman M, Elson D, Mylonas Get al., 2020, LaryngoTORS: a novel cable-driven parallel robotic system for transoral laser phonosurgery, IEEE Robotics and Automation Letters, Vol: 5, Pages: 1516-1523, ISSN: 2377-3766

Transoral laser phonosurgery is a commonly used surgical procedure in which a laser beam is used to perform incision, ablation or photocoagulation of laryngeal tissues. Two techniques are commonly practiced: free beam and fiber delivery. For free beam delivery, a laser scanner is integrated into a surgical microscope to provide an accurate laser scanning pattern. This approach can only be used under direct line of sight, which may cause increased postoperative pain to the patient and injury, is uncomfortable for the surgeon during prolonged operations, the manipulability is poor and extensive training is required. In contrast, in the fiber delivery technique, a flexible fiber is used to transmit the laser beam and therefore does not require direct line of sight. However, this can only achieve manual level accuracy, repeatability and velocity, and does not allow for pattern scanning. Robotic systems have been developed to overcome the limitations of both techniques. However, these systems offer limited workspace and degrees-of-freedom (DoF), limiting their clinical applicability. This work presents the LaryngoTORS, a robotic system that aims at overcoming the limitations of the two techniques, by using a cable-driven parallel mechanism (CDPM) attached at the end of a curved laryngeal blade for controlling the end tip of the laser fiber. The system allows autonomous generation of scanning patterns or user driven freepath scanning. Path scan validation demonstrated errors as low as 0.054±0.028 mm and high repeatability of 0.027±0.020 mm (6×2 mm arc line). Ex vivo tests on chicken tissue have been carried out. The results show the ability of the system to overcome limitations of current methods with high accuracy and repeatability using the superior fiber delivery approach.

Journal article

Runciman M, Avery J, Zhao M, Darzi A, Mylonas GPet al., 2020, Deployable, variable stiffness, cable driven robot for minimally invasive surgery, Frontiers in Robotics and AI, Vol: 6, Pages: 1-16, ISSN: 2296-9144

Minimally Invasive Surgery (MIS) imposes a trade-off between non-invasive access and surgical capability. Treatment of early gastric cancers over 20 mm in diameter can be achieved by performing Endoscopic Submucosal Dissection (ESD) with a flexible endoscope; however, this procedure is technically challenging, suffers from extended operation times and requires extensive training. To facilitate the ESD procedure, we have created a deployable cable driven robot that increases the surgical capabilities of the flexible endoscope while attempting to minimize the impact on the access that they offer. Using a low-profile inflatable support structure in the shape of a hollow hexagonal prism, our robot can fold around the flexible endoscope and, when the target site has been reached, achieve a 73.16% increase in volume and increase its radial stiffness. A sheath around the variable stiffness structure delivers a series of force transmission cables that connect to two independent tubular end-effectors through which standard flexible endoscopic instruments can pass and be anchored. Using a simple control scheme based on the length of each cable, the pose of the two instruments can be controlled by haptic controllers in each hand of the user. The forces exerted by a single instrument were measured, and a maximum magnitude of 8.29 N observed along a single axis. The working channels and tip control of the flexible endoscope remain in use in conjunction with our robot and were used during a procedure imitating the demands of ESD was successfully carried out by a novice user. Not only does this robot facilitate difficult surgical techniques, but it can be easily customized and rapidly produced at low cost due to a programmatic design approach.

Journal article

Zhao M, Zhang H, Mylonas GP, Elson DSet al., 2020, Cable-driven parallel robot assisted confocal imaging of the larynx

© OSA 2020 © 2020 The Author(s) LaryngoTORS, a transoral laryngeal surgery robot, can manipulate instruments accurately. Confocal imaging has potentials in laryngeal cancer diagnosis but suffer from high scanning requirement. This work studies using LaryngoTORS to assist confocal imaging of larynx.

Conference paper

Ezzat A, Thakkar R, Kogkas A, Mylonas Get al., 2019, Perceptions of surgeons and scrub nurses towards a novel eye-tracking based robotic scrub nurse platform, International Surgical Congress of the Association-of-Surgeons-of-Great-Britain-and-Ireland (ASGBI), Publisher: WILEY, Pages: 81-82, ISSN: 0007-1323

Conference paper

Avery J, Runciman M, Darzi A, Mylonas GPet al., 2019, Shape sensing of variable stiffness soft robots using electrical impedance tomography, International Conference on Robotics and Automation (ICRA), Publisher: IEEE, Pages: 9066-9072, ISSN: 1050-4729

Soft robotic systems offer benefits over traditional rigid systems through reduced contact trauma with soft tissues and by enabling access through tortuous paths in minimally invasive surgery. However, the inherent deformability of soft robots places both a greater onus on accurate modelling of their shape, and greater challenges in realising intraoperative shape sensing. Herein we present a proprioceptive (self-sensing) soft actuator, with an electrically conductive working fluid. Electrical impedance measurements from up to six electrodes enabled tomographic reconstructions using Electrical Impedance Tomography (EIT). A new Frequency Division Multiplexed (FDM) EIT system was developed capable of measurements of 66 dB SNR with 20 ms temporal resolution. The concept was examined in two two-degree-of-freedom designs: a hydraulic hinged actuator and a pneumatic finger actuator with hydraulic beams. Both cases demonstrated that impedance measurements could be used to infer shape changes, and EIT images reconstructed during actuation showed distinct patterns with respect to each degree of freedom (DOF). Whilst there was some mechanical hysteresis observed, the repeatability of the measurements and resultant images was high. The results show the potential of FDM-EIT as a low-cost, low profile shape sensor in soft robots.

Conference paper

Runciman M, Darzi A, Mylonas G, 2019, Soft robotics in minimally invasive surgery, Soft Robotics, Vol: 6, Pages: 423-443, ISSN: 2169-5172

Soft robotic devices have desirable traits for applications in minimally invasive surgery (MIS) but many interdisciplinary challenges remain unsolved. To understand current technologies, we carried out a keyword search using the Web of Science and Scopus databases, applied inclusion and exclusion criteria, and compared several characteristics of the soft robotic devices for MIS in the resulting articles. There was low diversity in the device designs and a wide-ranging level of detail regarding their capabilities. We propose a standardised comparison methodology to characterise soft robotics for various MIS applications, which will aid designers producing the next generation of devices.

Journal article

Fathi J, Vrielink TJCO, Runciman MS, Mylonas GPet al., 2019, A Deployable Soft Robotic Arm with Stiffness Modulation for Assistive Living Applications, International Conference on Robotics and Automation (ICRA), Publisher: IEEE, Pages: 1479-1485, ISSN: 1050-4729

Conference paper

Patel N, Kogkas A, Ben Glover AD, Mylonas Get al., 2019, EYE GAZE-CONTROLLED ROBOTIC FLEXIBLE ENDOSCOPY: A FEASIBILITY STUDY, Annual Meeting of the British-Society-of-Gastroenterology (BSG), Publisher: BMJ PUBLISHING GROUP, Pages: A38-A39, ISSN: 0017-5749

Conference paper

Vrielink TJCO, Puyal JG-B, Kogkas A, Darzi A, Mylonas Get al., 2019, Intuitive Gaze-Control of a Robotized Flexible Endoscope, 25th IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, Pages: 1776-1782, ISSN: 2153-0858

Conference paper

Wang M-Y, Kogkas AA, Darzi A, Mylonas GPet al., 2019, Free-view, 3D gaze-guided, assistive robotic system for activities of daily living, 25th IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, Pages: 2355-2361, ISSN: 2153-0858

Patients suffering from quadriplegia have limited body motion which prevents them from performing daily activities. We have developed an assistive robotic system with an intuitive free-view gaze interface. The user's point of regard is estimated in 3D space while allowing free head movement and is combined with object recognition and trajectory planning. This framework allows the user to interact with objects using fixations. Two operational modes have been implemented to cater for different eventualities. The automatic mode performs a pre-defined task associated with a gaze-selected object, while the manual mode allows gaze control of the robot's end-effector position on the user's frame of reference. User studies reported effortless operation in automatic mode. A manual pick and place task achieved a success rate of 100% on the users' first attempt.

Conference paper

Achanccaray D, Mylonas G, Andreu-Perez J, 2019, An Implicit Brain Computer Interface Supported by Gaze Monitoring for Virtual Therapy, IEEE International Conference on Systems, Man and Cybernetics (SMC), Publisher: IEEE, Pages: 2829-2832, ISSN: 1062-922X

Conference paper

Zhao M, Oude Vrielink J, Kogkas A, Mylonas G, Elson Det al., 2019, Prototype Designs of a Cable-driven Parallel Robot for Transoral Laser Surgery, Hamlyn Symposium on Medical Robotics

Conference paper

Kogkas A, Ezzat A, Thakkar R, Darzi A, Mylonas Get al., 2019, Free-View, 3D Gaze-Guided Robotic Scrub Nurse, Editors: Shen, Liu, Peters, Staib, Essert, Zhou, Yap, Khan, Publisher: SPRINGER INTERNATIONAL PUBLISHING AG, Pages: 164-172, ISBN: 978-3-030-32253-3

Book chapter

Oude Vrielink TJC, Vitiello V, Mylonas GP, 2019, Robotic surgery in cancer, Bioengineering Innovative Solutions for Cancer, Pages: 245-269, ISBN: 9780128138878

© 2020 Elsevier Ltd. All rights reserved. Cancer is responsible for the death of thousands of people around the world. When diagnosed and treated at an early stage, long-term survival rates are very high, and today advanced screening has considerably improved early cancer detection and diagnosis. The contemporary view is that surgical cancer removal should also aim at minimizing the external and internal trauma to the patient, for improved postoperative healing and cosmesis. Toward these two goals, minimally invasive surgery (MIS) approaches strive for organ-sparing-as opposed to radical-surgery, using miniaturized surgical instruments introduced through small incisions on the patient skin, or through natural orifices. The operational challenges of such approaches are obvious. Robotic surgery, still in its infancy, is known to improve surgical practice. However, certain operational challenges remain and clear long-term evidence about the superior curative outcomes of robotic surgery over conventional approaches is a subject of debate. This chapter introduces MIS, discusses its limitations for both conventional and robotic approaches, and highlights future opportunities for improving surgical outcomes. Gastrointestinal cancer surgery is used as a representative case study.

Book chapter

Vrielink TJCO, Chao M, Darzi A, Mylonas GPet al., 2018, ESD CYCLOPS: A new robotic surgical system for GI surgery, IEEE International Conference on Robotics and Automation (ICRA), Publisher: IEEE Computer Soc., Pages: 150-157, ISSN: 1050-4729

Gastrointestinal (GI) cancers account for 1.5 million deaths worldwide. Endoscopic Submucosal Dissection (ESD) is an advanced therapeutic endoscopy technique with superior clinical outcome due to the minimally invasive and en bloc removal of tumours. In the western world, ESD is seldom carried out, due to its complex and challenging nature. Various surgical systems are being developed to make this therapy accessible, however, these solutions have shown limited operational workspace, dexterity, or low force exertion capabilities. The current paper shows the ESD CYCLOPS system, a bimanual surgical robotic attachment that can be mounted at the end of any flexible endoscope. The system is able to achieve forces of up to 46N, and showed a mean error of 0.217mm during an elliptical tracing task. The workspace and instrument dexterity is shown by pre-clinical ex vivo trials, in which ESD is successfully performed by a GI surgeon. The system is currently undergoing pre-clinical in vivo validation.

Conference paper

Pittiglio G, Kogkas A, Vrielink JO, Mylonas Get al., 2018, Dynamic Control of Cable Driven Parallel Robots with Unknown Cable Stiffness: a Joint Space Approach, IEEE International Conference on Robotics and Automation (ICRA), Publisher: IEEE COMPUTER SOC, Pages: 948-955, ISSN: 1050-4729

Conference paper

Runciman M, Darzi A, Mylonas G, 2018, Deployable disposable self-propelling and variable stiffness devices for minimally invasive surgery, Conference on New Technologies for Computer/Robot Assisted Surgery

Conference paper

Miyashita K, Oude Vrielink T, Mylonas G, 2018, A cable-driven parallel manipulator with force sensing capabilities for high-accuracy tissue endomicroscopy, International Journal of Computer Assisted Radiology and Surgery, Vol: 13, Pages: 659-669, ISSN: 1861-6429

PURPOSE: Endomicroscopy (EM) provides high resolution, non-invasive histological tissue information and can be used for scanning of large areas of tissue to assess cancerous and pre-cancerous lesions and their margins. However, current robotic solutions do not provide the accuracy and force sensitivity required to perform safe and accurate tissue scanning. METHODS: A new surgical instrument has been developed that uses a cable-driven parallel mechanism (CPDM) to manipulate an EM probe. End-effector forces are determined by measuring the tensions in each cable. As a result, the instrument allows to accurately apply a contact force on a tissue, while at the same time offering high resolution and highly repeatable probe movement. RESULTS: 0.2 and 0.6 N force sensitivities were found for 1 and 2 DoF image acquisition methods, respectively. A back-stepping technique can be used when a higher force sensitivity is required for the acquisition of high quality tissue images. This method was successful in acquiring images on ex vivo liver tissue. CONCLUSION: The proposed approach offers high force sensitivity and precise control, which is essential for robotic EM. The technical benefits of the current system can also be used for other surgical robotic applications, including safe autonomous control, haptic feedback and palpation.

Journal article

Avila Rencoret FB, Mylonas G, Elson D, 2018, Robotic wide-field optical biopsy endoscopy, OSA Biophotonics Congress 2018, Publisher: OSA publishing

This paper describes a novel robotic framework for wide-field optical biopsy endoscopy, characterizes in vitro its spatial and spectral resolution, real time hyperspectral tissue classification, and demonstrates its feasibility on fresh porcine cadaveric colon.

Conference paper

Avila Rencoret FB, Mylonas GP, Elson D, 2018, Robotic Wide-Field Optical Biopsy Imaging For Flexible Endoscopy, 26th International Congress of the European Association for Endoscopic Surgery (EAES)

Conference paper

Zhao M, Oude Vrielink T, Elson D, Mylonas Get al., 2018, Endoscopic TORS-CYCLOPS: A Novel Cable-driven Parallel Robot for Transoral Laser Surgery, 26th Annual International EAES Congress

Conference paper

Elson D, Avila Rencoret F, Mylonas G, 2018, Robotic Wide-Field Optical Biopsy Imaging for Flexible Endoscopy (Gerhard Buess Technology Award), 26th Annual International EAES Congress

Conference paper

Ashraf H, Sodergren M, Merali N, Mylonas G, Singh H, Darzi Aet al., 2017, Eye-tracking technology in medical education: A systematic review, Medical Teacher, Vol: 40, Pages: 62-69, ISSN: 0142-159X

Background: Eye-tracking technology is an established research tool within allied industries such as advertising, psychology and aerospace. This review aims to consolidate literature describing the evidence for use of eye-tracking as an adjunct to traditional teaching methods in medical education.Methods: A systematic literature review was conducted in line with STORIES guidelines. A search of EMBASE, OVID MEDLINE, PsycINFO, TRIP database, and Science Direct was conducted until January 2017. Studies describing the use of eye-tracking in the training, assessment, and feedback of clinicians were included in the review.Results: Thirty-three studies were included in the final qualitative synthesis. Three studies were based on the use of gaze training, three studies on the changes in gaze behavior during the learning curve, 17 studies on clinical assessment and six studies focused on the use of eye-tracking methodology as a feedback tool. The studies demonstrated feasibility and validity in the use of eye-tracking as a training and assessment method.Conclusions: Overall, eye-tracking methodology has contributed significantly to the training, assessment, and feedback practices used in the clinical setting. The technology provides reliable quantitative data, which can be interpreted to give an indication of clinical skill, provide training solutions and aid in feedback and reflection. This review provides a detailed summary of evidence relating to eye-tracking methodology and its uses as a training method, changes in visual gaze behavior during the learning curve, eye-tracking methodology for proficiency assessment and its uses as a feedback tool.

Journal article

Kogkas AA, Darzi A, Mylonas GP, 2017, Gaze-contingent perceptually enabled interactions in the operating theatre., International Journal of Computer Assisted Radiology and Surgery, Vol: 12, Pages: 1131-1140, ISSN: 1861-6410

PURPOSE: Improved surgical outcome and patient safety in the operating theatre are constant challenges. We hypothesise that a framework that collects and utilises information -especially perceptually enabled ones-from multiple sources, could help to meet the above goals. This paper presents some core functionalities of a wider low-cost framework under development that allows perceptually enabled interaction within the surgical environment. METHODS: The synergy of wearable eye-tracking and advanced computer vision methodologies, such as SLAM, is exploited. As a demonstration of one of the framework's possible functionalities, an articulated collaborative robotic arm and laser pointer is integrated and the set-up is used to project the surgeon's fixation point in 3D space. RESULTS: The implementation is evaluated over 60 fixations on predefined targets, with distances between the subject and the targets of 92-212 cm and between the robot and the targets of 42-193 cm. The median overall system error is currently 3.98 cm. Its real-time potential is also highlighted. CONCLUSIONS: The work presented here represents an introduction and preliminary experimental validation of core functionalities of a larger framework under development. The proposed framework is geared towards a safer and more efficient surgical theatre.

Journal article

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