144 research outputs found

    Shared-Control Teleoperation Paradigms on a Soft Growing Robot Manipulator

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    Semi-autonomous telerobotic systems allow both humans and robots to exploit their strengths, while enabling personalized execution of a task. However, for new soft robots with degrees of freedom dissimilar to those of human operators, it is unknown how the control of a task should be divided between the human and robot. This work presents a set of interaction paradigms between a human and a soft growing robot manipulator, and demonstrates them in both real and simulated scenarios. The robot can grow and retract by eversion and inversion of its tubular body, a property we exploit to implement interaction paradigms. We implemented and tested six different paradigms of human-robot interaction, beginning with full teleoperation and gradually adding automation to various aspects of the task execution. All paradigms were demonstrated by two expert and two naive operators. Results show that humans and the soft robot manipulator can split control along degrees of freedom while acting simultaneously. In the simple pick-and-place task studied in this work, performance improves as the control is gradually given to the robot, because the robot can correct certain human errors. However, human engagement and enjoyment may be maximized when the task is at least partially shared. Finally, when the human operator is assisted by haptic feedback based on soft robot position errors, we observed that the improvement in performance is highly dependent on the expertise of the human operator.Comment: 15 pages, 14 figure

    The Use of Skeletal Muscle to Amplify Action Potentials in Transected Peripheral Nerves

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    Upper limb amputees suffer with problems associated with control and attachment of prostheses. Skin-surface electrodes placed over the stump, which detect myoelectric signals, are traditionally used to control hand movements. However, this method is unintuitive, the electrodes lift-off, and signal selectivity can be an issue. One solution to these limitations is to implant electrodes directly on muscles. Another approach is to implant electrodes directly into the nerves that innervate the muscles. A significant challenge with both solutions is the reliable transmission of biosignals across the skin barrier. In this thesis, I investigated the use of implantable muscle electrodes in an ovine model using myoelectrodes in combination with a bone-anchor, acting as a conduit for signal transmission. High-quality readings were obtained which were significantly better than skin-surface electrode readings. I further investigated the effect of electrode configurations to achieve the best signal quality. For direct recording from nerves, I tested the effect of adsorbed endoneural basement membrane proteins on nerve regeneration in vivo using microchannel neural interfaces implanted in rat sciatic nerves. Muscle and nerve signal recordings were obtained and improvements in sciatic nerve function were observed. Direct skeletal fixation of a prosthesis to the amputation stump using a bone-anchor has been proposed as a solution to skin problems associated with traditional socket-type prostheses. However, there remains a concern about the risk of infection between the implant and skin. Achieving a durable seal at this interface is therefore crucial, which formed the final part of the thesis. Bone-anchors were optimised for surface pore size and coatings to facilitate binding of human dermal fibroblasts to optimise skin-implant seal in an ovine model. Implants silanised with Arginine-Glycine-Aspartic Acid experienced significantly increased dermal tissue infiltration. This approach may therefore improve the soft tissue seal, and thus success of bone-anchored implants. By addressing both the way prostheses are attached to the amputation stump, by way of direct skeletal fixation, as well as providing high fidelity biosignals for high-level intuitive prosthetic control, I aim to further the field of limb loss rehabilitation

    Control and Estimation Methods Towards Safe Robot-assisted Eye Surgery

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    Vitreoretinal surgery is among the most delicate surgical tasks in which physiological hand tremor may severely diminish surgeon performance and put the eye at high risk of injury. Unerring targeting accuracy is required to perform precise operations on micro-scale tissues. Tool tip to tissue interaction forces are usually below human tactile perception, which may result in exertion of excessive forces to the retinal tissue leading to irreversible damages. Notable challenges during retinal surgery lend themselves to robotic assistance which has proven beneficial in providing a safe steady-hand manipulation. Efficient assistance from the robots heavily relies on accurate sensing and intelligent control algorithms of important surgery states and situations (e.g. instrument tip position measurements and control of interaction forces). This dissertation provides novel control and state estimation methods to improve safety during robot-assisted eye surgery. The integration of robotics into retinal microsurgery leads to a reduction in surgeon perception of tool-to-tissue forces at sclera. This blunting of human tactile sensory input, which is due to the inflexible inertia of the robot, is a potential iatrogenic risk during robotic eye surgery. To address this issue, a sensorized surgical instrument equipped with Fiber Bragg Grating (FBG) sensors, which is capable of measuring the sclera forces and instrument insertion depth into the eye, is integrated to the Steady-Hand Eye Robot (SHER). An adaptive control scheme is then customized and implemented on the robot that is intended to autonomously mitigate the risk of unsafe scleral forces and excessive insertion of the instrument. Various preliminary and multi-user clinician studies are then conducted to evaluate the effectiveness of the control method during mock retinal surgery procedures. In addition, due to inherent flexibility and the resulting deflection of eye surgical instruments as well as the need for targeting accuracy, we have developed a method to enhance deflected instrument tip position estimation. Using an iterative method and microscope data, we develop a calibration- and registration-independent (RI) framework to provide online estimates of the instrument stiffness (least squares and adaptive). The estimations are then combined with a state-space model for tip position evolution obtained based on the forward kinematics (FWK) of the robot and FBG sensor measurements. This is accomplished using a Kalman Filtering (KF) approach to improve the instrument tip position estimation during robotic surgery. The entire framework is independent of camera-to-robot coordinate frame registration and is evaluated during various phantom experiments to demonstrate its effectiveness

    Visualization, navigation, augmentation. The ever-changing perspective of the neurosurgeon

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    Introduction: The evolution of neurosurgery coincides with the evolution of visualization and navigation. Augmented reality technologies, with their ability to bring digital information into the real environment, have the potential to provide a new, revolutionary perspective to the neurosurgeon. Research question: To provide an overview on the historical and technical aspects of visualization and navigation in neurosurgery, and to provide a systematic review on augmented reality (AR) applications in neurosurgery. Material and methods: We provided an overview on the main historical milestones and technical features of visualization and navigation tools in neurosurgery. We systematically searched PubMed and Scopus databases for AR applications in neurosurgery and specifically discussed their relationship with current visualization and navigation systems, as well as main limitations. Results: The evolution of visualization in neurosurgery is embodied by four magnification systems: surgical loupes, endoscope, surgical microscope and more recently the exoscope, each presenting independent features in terms of magnification capabilities, eye-hand coordination and the possibility to implement additional functions. In regard to navigation, two independent systems have been developed: the frame-based and the frame-less systems. The most frequent application setting for AR is brain surgery (71.6%), specifically neuro-oncology (36.2%) and microscope-based (29.2%), even though in the majority of cases AR applications presented their own visualization supports (66%). Discussion and conclusions: The evolution of visualization and navigation in neurosurgery allowed for the development of more precise instruments; the development and clinical validation of AR applications, have the potential to be the next breakthrough, making surgeries safer, as well as improving surgical experience and reducing costs

    Principles of human movement augmentation and the challenges in making it a reality

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    Augmenting the body with artificial limbs controlled concurrently to one's natural limbs has long appeared in science fiction, but recent technological and neuroscientific advances have begun to make this possible. By allowing individuals to achieve otherwise impossible actions, movement augmentation could revolutionize medical and industrial applications and profoundly change the way humans interact with the environment. Here, we construct a movement augmentation taxonomy through what is augmented and how it is achieved. With this framework, we analyze augmentation that extends the number of degrees-of-freedom, discuss critical features of effective augmentation such as physiological control signals, sensory feedback and learning as well as application scenarios, and propose a vision for the field

    Optimising breast reconstruction. A clinical study on autologous breast reconstruction

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    Denne avhandlingen omhandler metoder for å optimalisere utfallet av brystrekonstruksjon ved bruk av kroppseget vev. Det første delarbeidet beskriver en kirurgisk teknikk som kombinerer to lapper fra henholdsvis buken (DIEP og TRAM lapper) og ytre deler av brystkassen (LICAP lapp) for å oppnå større volum og penere fasong på det rekonstruerte brystet hos kvinner med lite overskuddsvev på buken. LICAP lapp til brystrekonstruksjon er tidligere beskrevet, men en ny design på lappen resulterte i et bedre estetisk resultat enn med tidligere brukt teknikk. Det andre delarbeidet beskriver verdien termografi for å kartlegge lokalisasjonen av blodkar under huden (perforanter) til i planlegging av brystrekonstruksjon ved bruk av lapper fra øvre del av ryggen (TDAP lapp). Samme visualiseringsteknikk ble også funnet nyttig under og etter kirurgisk behandling for å overvåke blodforsyningen i det rekonstruerte brystet. Termografi er gunstig ved at en unngår potensielt farlige og mer arbeidskrevende teknikker som baseres på røntgenstråling eller intravenøse kontrastmidler, som ellers er hyppig brukt. Tidligere studier av intravenøs væskebehandling ved større kirurgi har vist at altfor liberal væsketilførsel kan øke risikoen for komplikasjoner og forlenge sykehusoppholdet. I det tredje delarbeidet ble to forskjellige strategier for intraoperativ væskebehandling sammenlignet, i forbindelse med mikrokirurgisk brystrekonstruksjon ved abdominale lapper. Resultatene viste at en restriktiv intravenøs væskebehandling i kombinasjon med bruk av noradrenalin og propofol, for å motvirke blodtrykksfall og gi økt blodforsyning til det transplantert vevet, var forenlig med færre komplikasjoner og kortere sykeleie. Spesielt forekom komplikasjoner relatert til det transplanterte vevet i betydelig mindre grad i pasientgruppen med lavere total intraoperativ væskevolum. Kombinasjon av lappeplastikker ved mikrokirurgisk brystrekonstruksjon, termografi for å sikre adekvat blodforsyning og en restriktiv intraoperativ væsketerapi er faktorer som kan bidra til er bedre resultat og mindre risiko ved avansert rekonstruktiv brystkirurgi.Breast reconstruction using the patient’s own tissue is common, but the surgical procedures can be complex. This project evaluated new methods to reduce the risks for complications and improve overall outcome after such surgery. In patients with limited surplus tissue on the lower abdomen, larger breast volume and improved aesthetic outcome was achieved when an abdominal free tissue transplant was combined with a local flap from the axillary area. Registration of heat radiation from the skin surface proved a valuable and safe technique to ensure proper flap design before tissue transplantation and to monitor flap blood perfusion during and after surgery, enabling swift correction of compromised flap perfusion. On assessment of intraoperative fluid management, a restricted fluid infusion combined with vasoactive drugs to ensure adequate blood pressure was correlated with less postoperative complications and shorter hospital stay as compared to a more liberal fluid management

    Mastering Endo-Laparoscopic and Thoracoscopic Surgery

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    This is an open access book. The book focuses mainly on the surgical technique, OR setup, equipments and devices necessary in minimally invasive surgery (MIS). It serves as a compendium of endolaparoscopic surgical procedures. It is an official publication of the Endoscopic and Laparoscopic Surgeons of Asia (ELSA). The book includes various sections covering basic skills set, devices, equipments, OR setup, procedures by area. Each chapter cover introduction, indications and contraindications, pre-operative patient’s assessment and preparation, OT setup (instrumentation required, patient’s position, etc.), step by step description of surgical procedures, management of complications, post-operative care. It includes original illustrations for better understanding and visualization of specific procedures. The book serves as a practical guide for surgical residents, surgical trainees, surgical fellows, junior surgeons, surgical consultants and anyone interested in MIS. It covers most of the basic and advanced laparoscopic and thoracoscopic surgery procedures meeting the curriculum and examination requirements of the residents

    Recent Advances in Minimally Invasive Surgery

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    Minimally invasive surgery has become a common term in visceral as well as gynecologic surgery. It has almost evolved into its own surgical speciality over the past 20 years. Today, being firmly established in every subspeciality of visceral surgery, it is now no longer a distinct skillset, but a fixed part of the armamentarium of surgical options available. In every indication, the advantages of a minimally invasive approach include reduced intraoperative blood loss, less postoperative pain, and shorter rehabilitation times, as well as a marked reduction of overall and surgical postoperative morbidity. In the advent of modern oncologic treatment algorithms, these effects not only lower the immediate impact that an operation has on the patient, but also become important key steps in reducing the side-effects of surgery. Thus, they enable surgery to become a module in modern multi-disciplinary cancer treatment, which blends into multimodular treatment options at different times and prolongs and widens the possibilities available to cancer patients. In this quickly changing environment, the requirement to learn and refine not only open surgical but also different minimally invasive techniques on high levels deeply impact modern surgical training pathways. The use of modern elearning tools and new and praxis-based surgical training possibilities have been readily integrated into modern surgical education,which persists throughout the whole surgical career of modern gynecologic and visceral surgery specialists
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