112 research outputs found

    A robotic microsurgical forceps for transoral laser microsurgery

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    Purpose: In transoral laser microsurgery (TLM), the close curved cylindrical structure of the laryngeal region offers functional challenges to surgeons who operate on its malignancies with rigid, single degree-of-freedom (DOF) forceps. These challenges include surgeon hand tremors, poor reachability, poor tissue surface perception, and reduced ergonomy in design. The integrated robotic microsurgical forceps presented here is capable of addressing the above challenges through tele-operated tissue manipulation in TLM. Methods: The proposed device is designed in compliance with the spatial constraints in TLM. It incorporates a novel 2-DOF motorized microsurgical forceps end-effector, which is integrated with a commercial 6-DOF serial robotic manipulator. The integrated device is tele-operated through the haptic master interface, Omega.7. The device is augmented with a force sensor to measure tissue gripping force. The device is called RMF-2F, i.e. robotic microsurgical forceps with 2-DOF end-effector and force sensing. RMF-2F is evaluated through validation trials and pick-n-place experiments with subjects. Furthermore, the device is trialled with expert surgeons through preliminary tasks in a simulated surgical scenario. Results: RMF-2F shows a motion tracking error of less than 400 μm. User trials demonstrate the device’s accuracy in task completion and ease of manoeuvrability using the Omega.7 through improved trajectory following and execution times. The tissue gripping force shows better regulation with haptic feedback (1.624 N) than without haptic feedback (2.116 N). Surgeons positively evaluated the device with appreciation for improved access in the larynx and gripping force feedback. Conclusions: RMF-2F offers an ergonomic and intuitive interface for intraoperative tissue manipulation in TLM. The device performance, usability, and haptic feedback capability were positively evaluated by users as well as expert surgeons. RMF-2F introduces the benefits of robotic teleoperation including, (i) overcoming hand tremors and wrist excursions, (ii) improved reachability and accuracy, and (iii) tissue gripping feedback for safe tissue manipulation

    A Review of Haptic Feedback Teleoperation Systems for Micromanipulation and Microassembly

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    International audienceThis paper presents a review of the major haptic feedback teleoperation systems for micromanipulation. During the last decade, the handling of micrometer-sized objects has become a critical issue. Fields of application from material science to electronics demonstrate an urgent need for intuitive and flexible manipulation systems able to deal with small-scale industrial projects and assembly tasks. Two main approaches have been considered: fully automated tasks and manual operation. The first one require fully pre determined tasks, while the later necessitates highly trained operators. To overcome these issues the use of haptic feedback teleoperation where the user manipulates the tool through a joystick whilst feeling a force feedback, appears to be a promising solution as it allows high intuitiveness and flexibility. Major advances have been achieved during this last decade, starting with systems that enable the operator to feel the substrate topology, to the current state-of-the-art where 3D haptic feedback is provided to aid manipulation tasks. This paper details the major achievements and the solutions that have been developed to propose 3D haptic feedback for tools that often lack 3D force measurements. The use of virtual reality to enhance the immersion is also addressed. The strategies developed provide haptic feedback teleoperation systems with a high degree of assistance and for a wide range of micromanipulation tools. Based on this expertise on haptic for micromanipulation and virtual reality assistance it is now possible to propose microassembly systems for objects as small as 1 to 10 micrometers. This is a mature field and will benefit small-scale industrial projects where precision and flexibility in microassembly are required

    Sensory substitution for force feedback recovery: A perception experimental study

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    Robotic-assisted surgeries are commonly used today as a more efficient alternative to traditional surgical options. Both surgeons and patients benefit from those systems, as they offer many advantages, including less trauma and blood loss, fewer complications, and better ergonomics. However, a remaining limitation of currently available surgical systems is the lack of force feedback due to the teleoperation setting, which prevents direct interaction with the patient. Once the force information is obtained by either a sensing device or indirectly through vision-based force estimation, a concern arises on how to transmit this information to the surgeon. An attractive alternative is sensory substitution, which allows transcoding information from one sensory modality to present it in a different sensory modality. In the current work, we used visual feedback to convey interaction forces to the surgeon. Our overarching goal was to address the following question: How should interaction forces be displayed to support efficient comprehension by the surgeon without interfering with the surgeon’s perception and workflow during surgery? Until now, the use the visual modality for force feedback has not been carefully evaluated. For this reason, we conducted an experimental study with two aims: (1) to demonstrate the potential benefits of using this modality and (2) to understand the surgeons’ perceptual preferences. The results derived from our study of 28 surgeons revealed a strong positive acceptance of the users (96%) using this modality. Moreover, we found that for surgeons to easily interpret the information, their mental model must be considered, meaning that the design of the visualizations should fit the perceptual and cognitive abilities of the end user. To our knowledge, this is the first time that these principles have been analyzed for exploring sensory substitution in medical robotics. Finally, we provide user-centered recommendations for the design of visual displays for robotic surgical systems.Peer ReviewedPostprint (author's final draft

    A continuum robotic platform for endoscopic non-contact laser surgery: design, control, and preclinical evaluation

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    The application of laser technologies in surgical interventions has been accepted in the clinical domain due to their atraumatic properties. In addition to manual application of fibre-guided lasers with tissue contact, non-contact transoral laser microsurgery (TLM) of laryngeal tumours has been prevailed in ENT surgery. However, TLM requires many years of surgical training for tumour resection in order to preserve the function of adjacent organs and thus preserve the patient’s quality of life. The positioning of the microscopic laser applicator outside the patient can also impede a direct line-of-sight to the target area due to anatomical variability and limit the working space. Further clinical challenges include positioning the laser focus on the tissue surface, imaging, planning and performing laser ablation, and motion of the target area during surgery. This dissertation aims to address the limitations of TLM through robotic approaches and intraoperative assistance. Although a trend towards minimally invasive surgery is apparent, no highly integrated platform for endoscopic delivery of focused laser radiation is available to date. Likewise, there are no known devices that incorporate scene information from endoscopic imaging into ablation planning and execution. For focusing of the laser beam close to the target tissue, this work first presents miniaturised focusing optics that can be integrated into endoscopic systems. Experimental trials characterise the optical properties and the ablation performance. A robotic platform is realised for manipulation of the focusing optics. This is based on a variable-length continuum manipulator. The latter enables movements of the endoscopic end effector in five degrees of freedom with a mechatronic actuation unit. The kinematic modelling and control of the robot are integrated into a modular framework that is evaluated experimentally. The manipulation of focused laser radiation also requires precise adjustment of the focal position on the tissue. For this purpose, visual, haptic and visual-haptic assistance functions are presented. These support the operator during teleoperation to set an optimal working distance. Advantages of visual-haptic assistance are demonstrated in a user study. The system performance and usability of the overall robotic system are assessed in an additional user study. Analogous to a clinical scenario, the subjects follow predefined target patterns with a laser spot. The mean positioning accuracy of the spot is 0.5 mm. Finally, methods of image-guided robot control are introduced to automate laser ablation. Experiments confirm a positive effect of proposed automation concepts on non-contact laser surgery.Die Anwendung von Lasertechnologien in chirurgischen Interventionen hat sich aufgrund der atraumatischen Eigenschaften in der Klinik etabliert. Neben manueller Applikation von fasergeführten Lasern mit Gewebekontakt hat sich die kontaktfreie transorale Lasermikrochirurgie (TLM) von Tumoren des Larynx in der HNO-Chirurgie durchgesetzt. Die TLM erfordert zur Tumorresektion jedoch ein langjähriges chirurgisches Training, um die Funktion der angrenzenden Organe zu sichern und damit die Lebensqualität der Patienten zu erhalten. Die Positionierung des mikroskopis chen Laserapplikators außerhalb des Patienten kann zudem die direkte Sicht auf das Zielgebiet durch anatomische Variabilität erschweren und den Arbeitsraum einschränken. Weitere klinische Herausforderungen betreffen die Positionierung des Laserfokus auf der Gewebeoberfläche, die Bildgebung, die Planung und Ausführung der Laserablation sowie intraoperative Bewegungen des Zielgebietes. Die vorliegende Dissertation zielt darauf ab, die Limitierungen der TLM durch robotische Ansätze und intraoperative Assistenz zu adressieren. Obwohl ein Trend zur minimal invasiven Chirurgie besteht, sind bislang keine hochintegrierten Plattformen für die endoskopische Applikation fokussierter Laserstrahlung verfügbar. Ebenfalls sind keine Systeme bekannt, die Szeneninformationen aus der endoskopischen Bildgebung in die Ablationsplanung und -ausführung einbeziehen. Für eine situsnahe Fokussierung des Laserstrahls wird in dieser Arbeit zunächst eine miniaturisierte Fokussieroptik zur Integration in endoskopische Systeme vorgestellt. Experimentelle Versuche charakterisieren die optischen Eigenschaften und das Ablationsverhalten. Zur Manipulation der Fokussieroptik wird eine robotische Plattform realisiert. Diese basiert auf einem längenveränderlichen Kontinuumsmanipulator. Letzterer ermöglicht in Kombination mit einer mechatronischen Aktuierungseinheit Bewegungen des Endoskopkopfes in fünf Freiheitsgraden. Die kinematische Modellierung und Regelung des Systems werden in ein modulares Framework eingebunden und evaluiert. Die Manipulation fokussierter Laserstrahlung erfordert zudem eine präzise Anpassung der Fokuslage auf das Gewebe. Dafür werden visuelle, haptische und visuell haptische Assistenzfunktionen eingeführt. Diese unterstützen den Anwender bei Teleoperation zur Einstellung eines optimalen Arbeitsabstandes. In einer Anwenderstudie werden Vorteile der visuell-haptischen Assistenz nachgewiesen. Die Systemperformanz und Gebrauchstauglichkeit des robotischen Gesamtsystems werden in einer weiteren Anwenderstudie untersucht. Analog zu einem klinischen Einsatz verfolgen die Probanden mit einem Laserspot vorgegebene Sollpfade. Die mittlere Positioniergenauigkeit des Spots beträgt dabei 0,5 mm. Zur Automatisierung der Ablation werden abschließend Methoden der bildgestützten Regelung vorgestellt. Experimente bestätigen einen positiven Effekt der Automationskonzepte für die kontaktfreie Laserchirurgie

    VerroTouch: High-Frequency Acceleration Feedback for Telerobotic Surgery

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    The Intuitive da Vinci system enables surgeons to see and manipulate structures deep within the body via tiny incisions. Though the robotic tools mimic one\u27s hand motions, surgeons cannot feel what the tools are touching, a striking contrast to non-robotic techniques. We have developed a new method for partially restoring this lost sense of touch. Our VerroTouch system measures the vibrations caused by tool contact and immediately recreates them on the master handles for the surgeon to feel. This augmentation enables the surgeon to feel the texture of rough surfaces, the start and end of contact with manipulated objects, and other important tactile events. While it does not provide low frequency forces, we believe vibrotactile feedback will be highly useful for surgical task execution, a hypothesis we we will test in future work

    Bilateral Macro-Micro Teleoperation Using A Magnetic Actuation Mechanism

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    In recent years, there has been increasing interest in the advancement of microrobotic systems in micro-engineering, micro-fabrication, biological research and biomedical applications. Untethered magnetic-based microrobotic systems are one of the most widely developing groups of microrobotic systems that have been extensively explored for biological and biomedical micro-manipulations. These systems show promise in resolving problems related to on-board power supply limitations as well as mechanical contact sealing and lubrication. In this thesis, a high precision magnetic untethered microrobotic system is demonstrated for micro-handling tasks. A key aspect of the proposed platform concerns the integration of magnetic levitation technology and bilateral macro-micro teleoperation for human intervention to avoid imperceptible failures in poorly observed micro-domain environments. The developed platform has three basic subsystems: a magnetic untethered microrobotic system (MUMS), a haptic device, and a scaled bilateral teleoperation system. The MUMS produces and regulates a magnetic field for non-contact propelling of a microrobot. In order to achieve a controlled motion of the magnetically levitated microrobot, a mathematical force model of the magnetic propulsion mechanism is developed and used to design various control systems. In the workspace of 30 × 32 × 32 mm 3, both PID and LQG\LTR controllers perform similarly the position accuracy of 10 µ m in a vertical direction and 2 µ m in a horizontal motion. The MUMS is equipped with an eddy-current damper to enhance its inherent damping factor in the microrobot's horizontal motions. This paper deals with the modeling and analysis of an eddy-current damper that is formed by a conductive plate placed below the levitated microrobot to overcome inherent dynamical vibrations and improve motion precision. The modeling of eddy-current distribution in the conductive plate is investigated by solving the diffusion equation for vector magnetic potential, and an analytical expression for the horizontal damping force is presented and experimentally validated. It is demonstrated that eddy-current damping is a crucial technique for increasing the damping coefficient in a non-contact way and for improving levitation performance. The damping can be widely used in applications of magnetic actuation systems in micro-manipulation and micro-fabrication. To determine the position of the microrobot in a workspace, the MUMS uses high-accuracy laser sensors. However, laser positioning techniques can only be used in highly transparent environments. A novel technique based on real-time magnetic flux measurement has been proposed for the position estimation of the microrobot in case of laser beam blockage, whereby a combination of Hall-effect sensors is employed to find the microrobot's position in free motion by using the produced magnetic flux. In free motion, the microrobot tends to move toward the horizontally zero magnetic field gradient, Bmax location. As another key feature of the magnetic flux measurement, it was realized that the applied force from the environment to the microrobot can be estimated as linearly proportional to the distance of the microrobot from the Bmax location. The developed micro-domain force estimation method is verified experimentally with an accuracy of 1.27 µ N. A bilateral macro-micro teleoperation technique is employed in the MUMS for the telepresence of a human operator in the task environment. A gain-switching position-position teleoperation scheme is employed and a human operator controls the motion of the microrobot via a master manipulator for dexterous micro-manipulation tasks. The operator can sense a strong force during micro-domain tasks if the microrobot encounters a stiff environment, and the effect of hard contact is fed back to the operator's hand. The position-position method works for both free motion and hard contact. However, to enhance the feeling of a micro-domain environment in the human operator, the scaled force must be transferred to a human, thereby realizing a direct-force-reflection bilateral teleoperation. Additionally, a human-assisted virtual reality interface is developed to improve a human operator's skills in using the haptic-enabled platform, before carrying out an actual dexterous task.1 yea
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