Imperial College London

Dr George Mylonas

Faculty of MedicineDepartment of Surgery & Cancer

Senior Lecturer in Robotics and Technology in Cancer
 
 
 
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Contact

 

george.mylonas Website

 
 
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Location

 

Room 415BBessemer BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

116 results found

Robertson D, Sterke F, van Weteringen W, Arezzo A, Mintz Y, Technology Committee of the European Association for Endoscopic Surgery EAES, Horeman Tet al., 2023, Escape of surgical smoke particles, comparing conventional and valveless trocar systems., Surg Endosc, Vol: 37, Pages: 8552-8561

BACKGROUND: During minimal access surgery, surgical smoke is produced which can potentially be inhaled by the surgical team, leading to several health risks. This smoke can escape from the abdominal cavity into the operating room due to trocar leakage. The trocars and insufflator that are used during surgery influence gas leakage. Therefore, this study compares particle escape from a valveless (Conmed AirSeal iFS), and a conventional (Karl Storz Endoflator) system. MATERIALS AND METHODS: Using an in vitro model, a conventional and a valveless trocar system were compared. A protocol that simulated various surgical phases was defined to assess the surgical conditions and particle leakage. Insufflation pressures and instrument diameters were varied as these are known to affect gas leakage. RESULTS: The conventional trocar leaked during two distinct phases. Removal of the obturator caused a sudden release of particles. During instrument insertion, an average of 211 (IQR 111) particles per second escaped when using the 5 mm diameter instrument. With the 10 mm instrument, 50 (IQR 13) particles per second were measured. With the conventional trocar, a higher abdominal pressure increased particle leakage. The valveless trocar demonstrated a continuously high particle release during all phases. After the obturator was removed, particle escape increased sharply. Particle escape decreased to 1276 (IQR 580) particles per second for the 5 mm instrument insertion, and 1084 (IQR 630) particles per second for 10 mm instrument insertion. With the valveless trocar system, a higher insufflation pressure lowered particle escape. CONCLUSIONS: This study shows that a valveless trocar system releases more particles into the operating room environment than a conventional trocar. During instrument insertion, the leakage through the valveless system is 6 to 20 times higher than the conventional system. With a valveless trocar, leakage decreases with increasing pressure. With both trocar type

Journal article

Robertson D, van Duijn M, Arezzo A, Mintz Y, Technology Committee of the EAES, Horeman-Franse Tet al., 2023, The influence of prolonged instrument manipulation on gas leakage through trocars., Surg Endosc, Vol: 37, Pages: 7325-7335

BACKGROUND: During laparoscopic surgery, CO2 insufflation gas could leak from the intra-abdominal cavity into the operating theater. Medical staff could therefore be exposed to hazardous substances present in leaked gas. Although previous studies have shown that leakage through trocars is a contributing factor, trocar performance over longer periods remains unclear. This study investigates the influence of prolonged instrument manipulation on gas leakage through trocars. METHODS: Twenty-five trocars with diameters ranging from 10 to 15 mm were included in the study. An experimental model was developed to facilitate instrument manipulation in a trocar under loading. The trocar was mounted to a custom airtight container insufflated with CO2 to a pressure of 15 mmHg, similar to clinical practice. A linear stage was used for prolonged instrument manipulation. At the same time, a fixed load was applied radially to the trocar cannula to mimic the reaction force of the abdominal wall. Gas leakage was measured before, after, and during instrument manipulation. RESULTS: After instrument manipulation, leakage rates per trocar varied between 0.0 and 5.58 L/min. No large differences were found between leakage rates before and after prolonged manipulation in static and dynamic measurements. However, the prolonged instrument manipulation did cause visible damage to two trocars and revealed unintended leakage pathways in others that can be related to production flaws. CONCLUSION: Prolonged instrument manipulation did not increase gas leakage rates through trocars, despite damage to some individual trocars. Nevertheless, gas leakage through trocars occurs and is caused by different trocar-specific mechanisms and design issues.

Journal article

Runciman M, Franco E, Avery J, Rodriguez y Baena F, Mylonas Get al., 2023, Model based position control of soft hydraulic actuators, IEEE International Conference on Robotics and Automation, Publisher: IEEE, Pages: 1-7

In this article, we investigate the model based position control of soft hydraulic actuators arranged in an an-tagonistic pair. A dynamical model of the system is constructed by employing the port-Hamiltonian formulation. A control algorithm is designed with an energy shaping approach, which accounts for the pressure dynamics of the fluid. A nonlinear observer is included to compensate the effect of unknown external forces. Simulations demonstrate the effectiveness of the proposed approach, and experiments achieve positioning accuracy of 0.043 mm with a standard deviation of 0.033 mm in the presence of constant external forces up to 1 N.

Conference paper

Sivananthan A, Kokgas A, Glover B, Darzi A, Mylonas G, Patel Net al., 2023, EYE CONTROLLED ENDOSCOPY - A BENCHTOP TRIAL OF A NOVEL ROBOTIC SYSTEM, Digestive Disease Week (DDW), Publisher: MOSBY-ELSEVIER, Pages: AB770-AB771, ISSN: 0016-5107

Conference paper

Alian A, Mylonas G, Avery J, 2023, Soft continuum actuator tip position and contact force prediction, using electrical impedance tomography and recurrent neural networks, IEEE International Conference on Soft Robotics (RoboSoft), Publisher: IEEE, Pages: 1-6, ISSN: 2769-4534

Enabling dexterous manipulation and safe human-robot interaction, soft robotsare widely used in numerous surgical applications. One of the complicationsassociated with using soft robots in surgical applications is reconstructingtheir shape and the external force exerted on them. Several sensor-based andmodel-based approaches have been proposed to address the issue. In this paper,a shape sensing technique based on Electrical Impedance Tomography (EIT) isproposed. The performance of this sensing technique in predicting the tipposition and contact force of a soft bending actuator is highlighted byconducting a series of empirical tests. The predictions were performed based ona data-driven approach using a Long Short-Term Memory (LSTM) recurrent neuralnetwork. The tip position predictions indicate the importance of using EIT dataalong with pressure inputs. Changing the number of EIT channels, we evaluatedthe effect of the number of EIT inputs on the accuracy of the predictions. Theleast RMSE values for the tip position are 3.6 and 4.6 mm in Y and Zcoordinates, respectively, which are 7.36% and 6.07% of the actuator's totalrange of motion. Contact force predictions were conducted in three differentbending angles and by varying the number of EIT channels. The results of thepredictions illustrated that increasing the number of channels contributes tohigher accuracy of the force estimation. The mean errors of using 8 channelsare 7.69%, 2.13%, and 2.96% of the total force range in three different bendingangles.

Conference paper

Avila-Rencoret F, Mylonas G, Elson D, 2023, Robotic large-area optical biopsy imaging for automated detection of gastrointestinal cancers tested in tissue phantoms and ex vivo porcine bowel, Translational Biophotonics, Vol: 5, ISSN: 2627-1850

Gastrointestinal endoscopy is a subjective procedure that frequently requires tissue samples for diagnosis. Contact optical biopsy (OB) techniques have the aim of providing direct diagnosis of endoscopic areas without excising tissue samples but lack the wide-area coverage required for locating and resecting lesions. This article presents a large-area robotically deployed OB imaging platform for endoscopic detection of colorectal cancer as an add-on for conventional endoscopes. In vitro, in silicon colon phantoms, the platform achieves an optical resolution of 0.5 line pairs per millimeter, while resolving simulated cancer lesions down to 0.75 mm diameter across large-area images (55-103 cm2). Large-area OB images were generated in an ex vivo porcine colon. The platform allows centimeter-sized large-area OB imaging in vitro and ex vivo with submillimeter resolution, including automatic data segmentation of simulated cancer areas. The ability for robotic actuation and spectrum collection is also shown for ex vivo animal colon. If successful, this technology could widen access to user-independent high-quality endoscopy and early detection of gastrointestinal cancers.

Journal article

Felinska EA, Fuchs TE, Kogkas A, Chen Z-W, Otto B, Kowalewski K-F, Petersen J, Mueller-Stich BP, Mylonas G, Nickel Fet al., 2023, Telestration with augmented reality improves surgical performance through gaze guidance, SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES, Vol: 37, Pages: 3557-3566, ISSN: 0930-2794

Journal article

Sivananthan A, Ahmed J, Kogkas A, Mylonas G, Darzi A, Patel Net al., 2023, Eye tracking technology in endoscopy: Looking to the future, DIGESTIVE ENDOSCOPY, Vol: 35, Pages: 314-322, ISSN: 0915-5635

Journal article

Alian A, Zari E, Wang Z, Franco E, Avery JP, Runciman M, Lo B, Rodriguez y Baena F, Mylonas Get al., 2023, Current engineering developments for robotic systems in flexible endoscopy, Techniques and Innovations in Gastrointestinal Endoscopy, Vol: 25, Pages: 67-81, ISSN: 2590-0307

The past four decades have seen an increase in the incidence of early-onset gastrointestinal cancer. Because early-stage cancer detection is vital to reduce mortality rate, mass screening colonoscopy provides the most effective prevention strategy. However, conventional endoscopy is a painful and technically challenging procedure that requires sedation and experienced endoscopists to be performed. To overcome the current limitations, technological innovation is needed in colonoscopy. In recent years, researchers worldwide have worked to enhance the diagnostic and therapeutic capabilities of endoscopes. The new frontier of endoscopic interventions is represented by robotic flexible endoscopy. Among all options, self-propelling soft endoscopes are particularly promising thanks to their dexterity and adaptability to the curvilinear gastrointestinal anatomy. For these devices to replace the standard endoscopes, integration with embedded sensors and advanced surgical navigation technologies must be investigated. In this review, the progress in robotic endoscopy was divided into the fundamental areas of design, sensing, and imaging. The article offers an overview of the most promising advancements on these three topics since 2018. Continuum endoscopes, capsule endoscopes, and add-on endoscopic devices were included, with a focus on fluid-driven, tendon-driven, and magnetic actuation. Sensing methods employed for the shape and force estimation of flexible endoscopes were classified into model- and sensor-based approaches. Finally, some key contributions in molecular imaging technologies, artificial neural networks, and software algorithms are described. Open challenges are discussed to outline a path toward clinical practice for the next generation of endoscopic devices.

Journal article

Alian A, Mylonas G, Avery J, 2023, Soft Continuum Actuator Tip Position and Contact Force Prediction, Using Electrical Impedance Tomography and Recurrent Neural Networks

Enabling dexterous manipulation and safe human-robot interaction, soft robots are widely used in numerous surgical applications. One of the complications associated with using soft robots in surgical applications is reconstructing their shape and the external force exerted on them. Several sensor-based and model-based approaches have been proposed to address the issue. In this paper, a shape sensing technique based on Electrical Impedance Tomography (EIT) is proposed. The performance of this sensing technique in predicting the tip position and contact force of a soft bending actuator is highlighted by conducting a series of empirical tests. The predictions were performed based on a data-driven approach using a Long Short-Term Memory (LSTM) recurrent neural network. The tip position predictions indicate the importance of using EIT data along with pressure inputs. Changing the number of EIT channels, we evaluated the effect of the number of EIT inputs on the accuracy of the predictions. The least RMSE values for the tip position are 3.6 and 4.6 mm in Y and Z coordinates, respectively, which are 7.36% and 6.07% of the actuator's total range of motion. Contact force predictions were conducted in three different bending angles and by varying the number of EIT channels. The results of the predictions illustrated that increasing the number of channels contributes to higher accuracy of the force estimation. The mean errors of using 8 channels are 7.69%, 2.13%, and 2.96% of the total force range in three different bending angles.

Conference paper

Maleki AN, Thompson A, Runciman MS, Murray J, Mylonas GPet al., 2023, A soft hydraulic endorectal actuator for prostate radiotherapy

Despite advances in radiotherapy, motion error remains a challenge in prostate radiotherapy. Rectal obturators and endorectal balloons may reduce motion error and improve outcomes but have limitations. We aimed to create a deployable rectal obturator with precise angle control to personalise to a patient's rectal anatomy, by using an antagonistic pair of "muscle"actuators to flex and extend the device. Results on deployability, angle control, and radial stiffness are presented here. The device can be compressed down to 16 x 3 x 91 mm, and be deployed to maximum dimensions of 24 x 25.5 x 77 mm. The device provides radial stiffness that may be sufficient to stabilise the rectum during radiotherapy. Angle control can be achieved with an average change of 7.5°/ml inflation in the extensor actuator.

Conference paper

Avery J, Runciman M, Fiani C, Monfort Sanchez E, Akhond S, Liu Z, Aristovich K, Mylonas Get al., 2022, Lumen shape reconstruction using a soft robotic balloon catheter andelectrical impedance tomography, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, ISSN: 2153-0866

Incorrectly sized balloon catheters can lead to increased post-surgical complications, yet even with preoperative imaging, correct selection remains a challenge. With limited feedback during surgery, it is difficult to verify correct deployment. We propose the use of integrated impedance measurements and Electrical Impedance Tomography (EIT) imaging to assess the deformation of the balloon and determine the size and shape of the surrounding lumen. Previous work using single impedance measurements, or pressure data and analytical models, whilst demonstrating high sizing accuracy, have assumed a circular cross section. Here we extend these methods by adding a multitude of electrodes to detect elliptical and occluded lumen and obtain EIT images to localise deformations. Using a 14 Fr (5.3 mm) catheter as an example, numerical simulations were performed to find the optimal electrode configuration of two rings of 8 electrodes spaced 10 mm apart. The simulations predicted that the maximum detectable aspect ratio decreased from 0.9 for a 14mm balloon to 0.5 at 30mm. The sizing and ellipticity detection results were verified experimentally. A prototype robotic balloon catheter was constructed to automatically inflate a compliant balloon while simultaneously recording EIT and pressure data. Data were collected in experiments replicating stenotic vessels with an elliptical and asymmetrical profile, and the widening of a lumen during angioplasty. After calibration, the system was able to correctly localise the occlusion and detect aspect ratios of 0.75. EIT images further localised the occlusion and visualised the dilation of the lumen during balloon inflation.

Conference paper

Naik R, Kogkas A, Ashrafian H, Mylonas G, Darzi Aet al., 2022, The Measurement of Cognitive Workload in Surgery Using Pupil Metrics: A Systematic Review and Narrative Analysis, JOURNAL OF SURGICAL RESEARCH, Vol: 280, Pages: 258-272, ISSN: 0022-4804

Journal article

Hardon SF, Rahimi AM, Postema RR, Willuth E, Mintz Y, Arezzo A, Dankelman J, Nickel F, Horeman T, EAES Technology Committee Study Groupet al., 2022, Safe implementation of hand held steerable laparoscopic instruments: a survey among EAES surgeons., Updates Surg, Vol: 74, Pages: 1749-1754

The complexity of handheld steerable laparoscopic instruments (SLI) may impair the learning curve compared to conventional instruments when first utilized. This study aimed to provide the current state of interest in the use of SLI, the current use of these in daily practice and the type of training which is conducted before using SLI in the operating room (OR) on real patients. An online survey was distributed by European Association of Endoscopic Surgery (EAES) Executive Office to all active members, between January 4th and February 3rd, 2020. The survey consisted of 14 questions regarding the usage and training of steerable laparoscopic instruments. A total of 83 members responded, coming from 33 different countries. Twenty three percent of the respondents using SLI, were using the instruments routinely and of these 21% had not received any formal training in advance of using the instruments in real patients. Of all responding EAES members, 41% considered the instruments to potentially compromise patient safety due to their complexity, learning curve and the inexperience of the surgeons. The respondents reported the three most important aspects of a possible steerable laparoscopic instruments training curriculum to be: hands-on training, safe tissue handling and suturing practice. Finally, a major part of the respondents consider force/pressure feedback data to be of significant importance for implementation of training and assessment of safe laparoscopic and robotic surgery. Training and assessment of skills regarding safe implementation of steerable laparoscopic instruments is lacking. The respondents stressed the need for specific hands-on training during which feedback and assessment of skills should be guaranteed before operating on real patients.

Journal article

DeLorey C, Davids JD, Cartucho J, Xu C, Roddan A, Nimer A, Ashrafian H, Darzi A, Thompson AJ, Akhond S, Runciman M, Mylonas G, Giannarou S, Avery Jet al., 2022, A cable‐driven soft robotic end‐effector actuator for probe‐based confocal laser endomicroscopy: Development and preclinical validation, Translational Biophotonics, ISSN: 2627-1850

Journal article

Liu T, Yang T, Xu W, Mylonas G, Liang Bet al., 2022, Efficient Inverse Kinematics and Planning of a Hybrid Active and Passive Cable-Driven Segmented Manipulator, IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS, Vol: 52, Pages: 4233-4246, ISSN: 2168-2216

Journal article

Robertson D, Sterke F, van Weteringen W, Arezzo A, Mintz Y, Nickel F, Technology committee of the European Association for Endoscopic Surgery EAES, Horeman Tet al., 2022, Characterisation of trocar associated gas leaks during laparoscopic surgery., Surg Endosc, Vol: 36, Pages: 4542-4551

BACKGROUND: During laparoscopy, the abdominal cavity is insufflated with carbon dioxide (CO2) that could become contaminated with viruses and surgical smoke. Medical staff is potentially exposed when this gas leaks into the operating room through the instruments and past trocar valves. No detailed studies currently exist that have quantified these leakage pathways. Therefore, the goal of this study was to quantify the gas leakages through trocars and instruments, during minimally invasive procedures. METHODS: A model of the surgical environment was created, consisting of a rigid container with an interface for airtight clamping of laparoscopic equipment such as trocars and surgical instruments. The model was insufflated to 15 mm Hg using a pressure generator and a pneumotachograph measured the equipment gas leak. A protocol of several use cases was designed to simulate the motions and forces the surgeon exerts on the trocar during surgery. RESULTS: Twenty-three individual trocars and twenty-six laparoscopic instruments were measured for leakage under the different conditions of the protocol. Trocar leakages varied between 0 L/min and more than 30 L/min, the instruments revealed a range of leakages between 0 L/min and 5.5 L/min. The results showed that leakage performance varied widely between trocars and instruments and that the performance and location of the valves influenced trocar leakage. CONCLUSIONS: We propose trocar redesigns to overcome specific causes of gas leaks. Moreover, an international testing standard for CO2 leakage for all new trocars and instruments is needed so surgical teams can avoid this potential health hazard when selecting new equipment.

Journal article

Arezzo A, Kruusmaa M, Mylonas G, 2022, Guest Editorial From Bench to Bedside, IEEE TRANSACTIONS ON MEDICAL ROBOTICS AND BIONICS, Vol: 4, Pages: 297-299

Journal article

Nakajima K, Mintz Y, Nickel F, Arezzo A, EAES Technology Committeeet al., 2022, The EAES intellectual property awareness survey., Surg Endosc, Vol: 36, Pages: 3340-3346

INTRODUCTION: The protection of intellectual property (IP) is one of the fundamental elements in the process of medical device development. The significance of IP, however, is not well understood among clinicians and researchers. The purpose of this study was to evaluate the current status of IP awareness and IP-related behaviors among EAES members. METHODS: A web-based survey was conducted via questionnaires sent to EAES members. Data collected included participant demographics, level of understanding the need, new ideas and solutions, basic IP knowledge, e.g., employees' inventions and public disclosure, behaviors before and after idea disclosures. RESULTS: One hundred and seventy-nine completed forms were obtained through an email campaign conducted twice in 2019 (response rate = 4.8%). There was a dominancy in male, formally-trained gastrointestinal surgeons, working at teaching hospitals in European countries. Of the respondents, 71% demonstrated a high level of understanding the needs (frustration with current medical devices), with 66% developing specific solutions by themselves. Active discussion with others was done by 53%. Twenty-one percent of respondents presented their ideas at medical congresses, and 12% published in scientific journals. Only 20% took specific precautions or appropriate actions to protect their IPs before these disclosures. CONCLUSIONS: The current level of awareness of IP and IP-related issues is relatively low among EAES members. A structured IP training program to gain basic IP knowledge and skill should be considered a necessity for clinicians. These skills would serve to prevent the loss of legitimate IP rights and avoid failure in the clinical implementation of innovative devices for the benefit of patients.

Journal article

Avery J, Runciman M, Fiani C, Sanchez EM, Akhond S, Liu Z, Aristovich K, Mylonas Get al., 2022, Lumen Shape Reconstruction using a Soft Robotic Balloon Catheter and Electrical Impedance Tomography, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, Pages: 3414-3421, ISSN: 2153-0858

Conference paper

Golahmadi AK, Khan DZ, Mylonas G, Marcus Het al., 2021, Tool-tissue Forces in Surgery: A Systematic Review, Publisher: ELSEVIER SCIENCE INC, Pages: E70-E70, ISSN: 1072-7515

Conference paper

Runciman M, Avery J, Darzi A, Mylonas Get al., 2021, Open loop position control of soft hydraulic actuators for minimally invasive surgery, Applied Sciences-Basel, Vol: 11, Pages: 1-16, ISSN: 2076-3417

Minimally invasive surgery (MIS) presents many constraints on the design of robotic devices that can assist medical staff with a procedure. The limitations of conventional, rigid robotic devices have sparked interest in soft robotic devices for medical applications. However, problems still remain with the force exertion and positioning capabilities of soft robotic actuators, in conjunction with size restrictions necessary for MIS. In this article we present hydraulically actuated soft actuators that demonstrate highly repeatable open loop positioning and the ability to exert significant forces in the context of MIS. Open loop position control is achieved by changing the actuator volume, which causes contraction. In one degree of freedom (DOF) configurations, root mean square error (RMSE) values of 0.471 mm, 1.506 mm, and 0.350 mm were recorded for a single actuator against gravity, a single actuator with a pulley, and a horizontal antagonistic configuration, respectively. Hysteresis values of 0.711 mm, 0.958 mm, and 0.515 mm were reported in these experiments. In addition, different numbers of soft actuators were used in configurations two and three DOFs to demonstrate position control. When deactivated, the soft actuators are low-profile and flexible as they are constructed from thin films. As such, a robot with a deployable structure and three soft actuators was constructed. The robot is therefore able to reversibly transition from low to high volume and stiffness, which has potential applications in MIS. A user successfully controlled the deployable robot in a circle tracing task.

Journal article

Kinross JM, Mason SE, Mylonas G, Darzi Aet al., 2021, Next-generation robotics in gastrointestinal surgery (vol 17, pg 430, 2020), NATURE REVIEWS GASTROENTEROLOGY & HEPATOLOGY, Vol: 18, Pages: 589-589, ISSN: 1759-5045

Journal article

Ezzat A, Kogkas A, Holt J, Thakkar R, Darzi A, Mylonas Get al., 2021, An eye-tracking based robotic scrub nurse: proof of concept, SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES, Vol: 35, Pages: 5381-5391, ISSN: 0930-2794

BackgroundWithin surgery, assistive robotic devices (ARD) have reported improved patient outcomes. ARD can offer the surgical team a “third hand” to perform wider tasks and more degrees of motion in comparison with conventional laparoscopy. We test an eye-tracking based robotic scrub nurse (RSN) in a simulated operating room based on a novel real-time framework for theatre-wide 3D gaze localization in a mobile fashion.MethodsSurgeons performed segmental resection of pig colon and handsewn end-to-end anastomosis while wearing eye-tracking glasses (ETG) assisted by distributed RGB-D motion sensors. To select instruments, surgeons (ST) fixed their gaze on a screen, initiating the RSN to pick up and transfer the item. Comparison was made between the task with the assistance of a human scrub nurse (HSNt) versus the task with the assistance of robotic and human scrub nurse (R&HSNt). Task load (NASA-TLX), technology acceptance (Van der Laan’s), metric data on performance and team communication were measured.ResultsOverall, 10 ST participated. NASA-TLX feedback for ST on HSNt vs R&HSNt usage revealed no significant difference in mental, physical or temporal demands and no change in task performance. ST reported significantly higher frustration score with R&HSNt. Van der Laan’s scores showed positive usefulness and satisfaction scores in using the RSN. No significant difference in operating time was observed.ConclusionsWe report initial findings of our eye-tracking based RSN. This enables mobile, unrestricted hands-free human–robot interaction intra-operatively. Importantly, this platform is deemed non-inferior to HSNt and accepted by ST and HSN test users.

Journal article

Sivananthan A, Kogkas A, Glover B, Darzi A, Mylonas G, Patel Net al., 2021, A novel gaze-controlled flexible robotized endoscope; preliminary trial and report, SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES, Vol: 35, Pages: 4890-4899, ISSN: 0930-2794

BackgroundInterventional endoluminal therapy is rapidly advancing as a minimally invasive surgical technique. The expanding remit of endoscopic therapy necessitates precision control. Eye tracking is an emerging technology which allows intuitive control of devices. This was a feasibility study to establish if a novel eye gaze-controlled endoscopic system could be used to intuitively control an endoscope.MethodsAn eye gaze-control system consisting of eye tracking glasses, specialist cameras and a joystick was used to control a robotically driven endoscope allowing steering, advancement, withdrawal and retroflexion. Eight experienced and eight non-endoscopists used both the eye gaze system and a conventional endoscope to identify ten targets in two simulated environments: a sphere and an upper gastrointestinal (UGI) model.Completion of tasks was timed. Subjective feedback was collected from each participant on task load (NASA Task Load Index) and acceptance of technology (Van der Laan scale).ResultsWhen using gaze-control endoscopy, non-endoscopists were significantly quicker when using gaze-control rather than conventional endoscopy (sphere task 3:54 ± 1:17 vs. 9:05 ± 5:40 min, p = 0.012, and UGI model task 1:59 ± 0:24 vs 3:45 ± 0:53 min, p < .001).Non-endoscopists reported significantly higher NASA-TLX workload total scores using conventional endoscopy versus gaze-control (80.6 ± 11.3 vs 22.5 ± 13.8, p < .001). Endoscopists reported significantly higher total NASA-TLX workload scores using gaze control versus conventional endoscopy (54.2 ± 16 vs 26.9 ± 15.3, p = 0.012). All subjects reported that the gaze-control had positive ‘usefulness’ and ‘satisfaction’ score of 0.56 ± 0.83 and 1.43 &

Journal article

Khan DZ, Kafai Golahmadi A, Mylonas G, Marcus Het al., 2021, 662 Tool-tissue Forces in Surgery: A Systematic Review, ASiT/MedAll Virtual Surgical Summit, Publisher: OXFORD UNIV PRESS, ISSN: 0007-1323

Conference paper

Ashraf H, Sodergren M, Mylonas G, Darzi Aet al., 2021, 837 The Identification of Gaze Behaviour and Physiological Markers Associated With Making An Error During Laparoscopic Cholecystectomy, ASiT/MedAll Virtual Surgical Summit, Publisher: OXFORD UNIV PRESS, ISSN: 0007-1323

Conference paper

Golahmadi AK, Khan DZ, Mylonas GP, Marcus HJet al., 2021, Tool-tissue forces in surgery: A systematic review, Annals of Medicine and Surgery, Vol: 65, Pages: 1-7, ISSN: 2049-0801

BackgroundExcessive tool-tissue interaction forces often result in tissue damage and intraoperative complications, while insufficient forces prevent the completion of the task. This review sought to explore the tool-tissue interaction forces exerted by instruments during surgery across different specialities, tissues, manoeuvres and experience levels.Materials & methodsA PRISMA-guided systematic review was carried out using Embase, Medline and Web of Science databases.ResultsOf 462 articles screened, 45 studies discussing surgical tool-tissue forces were included. The studies were categorized into 9 different specialities with the mean of average forces lowest for ophthalmology (0.04N) and highest for orthopaedic surgery (210N). Nervous tissue required the least amount of force to manipulate (mean of average: 0.4N), whilst connective tissue (including bone) required the most (mean of average: 45.8). For manoeuvres, drilling recorded the highest forces (mean of average: 14N), whilst sharp dissection recorded the lowest (mean of average: 0.03N). When comparing differences in the mean of average forces between groups, novices exerted 22.7% more force than experts, and presence of a feedback mechanism (e.g. audio) reduced exerted forces by 47.9%.ConclusionsThe measurement of tool-tissue forces is a novel but rapidly expanding field. The range of forces applied varies according to surgical speciality, tissue, manoeuvre, operator experience and feedback provided. Knowledge of the safe range of surgical forces will improve surgical safety whilst maintaining effectiveness. Measuring forces during surgery may provide an objective metric for training and assessment. Development of smart instruments, robotics and integrated feedback systems will facilitate this.

Journal article

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

BackgroundCOVID-19 pandemic presented an unexpected challenge for the surgical community in general and Minimally Invasive Surgery (MIS) specialists in particular. This document aims to summarize recent evidence and experts’ opinion and formulate recommendations to guide the surgical community on how to best organize the recovery plan for surgical activity across different sub-specialities after the COVID-19 pandemic.MethodsRecommendations were developed through a Delphi process for establishment of expert consensus. Domain topics were formulated and subsequently subdivided into questions pertinent to different surgical specialities following the COVID-19 crisis. Sixty-five experts from 24 countries, representing the entire EAES board, were invited. Fifty clinicians and six engineers accepted the invitation and drafted statements based on specific key questions. Anonymous voting on the statements was performed until consensus was achieved, defined by at least 70% agreement.ResultsA total of 92 consensus statements were formulated with regard to safe resumption of surgery across eight domains, addressing general surgery, upper GI, lower GI, bariatrics, endocrine, HPB, abdominal wall and technology/research. The statements addressed elective and emergency services across all subspecialties with specific attention to the role of MIS during the recovery plan. Eighty-four of the statements were approved during the first round of Delphi voting (91.3%) and another 8 during the following round after substantial modification, resulting in a 100% consensus.ConclusionThe recommendations formulated by the EAES board establish a framework for resumption of surgery following COVID-19 pandemic with particular focus on the role of MIS across surgical specialities. The statements have the potential for wide application in the clinical setting, education activities and research work across different healthcare systems.

Journal article

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