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Surgical Instruments (surgical + instruments)
Selected AbstractsImproving realism of a surgery simulator: linear anisotropic elasticity, complex interactions and force extrapolationCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3 2002Guillaume Picinbono Abstract In this article, we describe the latest developments of the minimally invasive hepatic surgery simulator prototype developed at INRIA. The goal of this simulator is to provide a realistic training test bed to perform laparoscopic procedures. Therefore, its main functionality is to simulate the action of virtual laparoscopic surgical instruments for deforming and cutting tridimensional anatomical models. Throughout this paper, we present the general features of this simulator including the implementation of several biomechanical models and the integration of two force-feedback devices in the simulation platform. More precisely, we describe three new important developments that improve the overall realism of our simulator. First, we have developed biomechanical models, based on linear elasticity and finite element theory, that include the notion of anisotropic deformation. Indeed, we have generalized the linear elastic behaviour of anatomical models to ,transversally isotropic' materials, i.e. materials having a different behaviour in a given direction. We have also added to the volumetric model an external elastic membrane representing the ,liver capsule', a rather stiff skin surrounding the liver, which creates a kind of ,surface anisotropy'. Second, we have developed new contact models between surgical instruments and soft tissue models. For instance, after detecting a contact with an instrument, we define specific boundary constraints on deformable models to represent various forms of interactions with a surgical tool, such as sliding, gripping, cutting or burning. In addition, we compute the reaction forces that should be felt by the user manipulating the force-feedback devices. The last improvement is related to the problem of haptic rendering. Currently, we are able to achieve a simulation frequency of 25,Hz (visual real time) with anatomical models of complex geometry and behaviour. But to achieve a good haptic feedback requires a frequency update of applied forces typically above 300,Hz (haptic real time). Thus, we propose a force extrapolation algorithm in order to reach haptic real time. Copyright © 2002 John Wiley & Sons, Ltd. [source] Ergonomics in Office-Based Surgery: A Survey-Guided Observational StudyDERMATOLOGIC SURGERY, Issue 11 2007ADAM C. ESSER MD BACKGROUND The practice of office-based surgery is increasing in many specialties. OBJECTIVE Using Mohs surgery as a model, we investigated the role of ergonomics in office-based surgery to limit work-related musculoskeletal disorders. METHODS All Mayo Clinic surgeons currently performing Mohs surgery and Mohs surgeons trained at Mayo Clinic between 1990 and 2004 received a questionnaire survey between May 2003 and September 2004. A sample of respondents were videotaped during surgery. The main outcome measures were survey responses and an ergonomist's identification of potential causes of musculoskeletal disorders. RESULTS All 17 surgeons surveyed responded. Those surveyed spend a mean of 24 hours per week in surgery. Sixteen said they had symptoms caused by or made worse by performing surgery. Symptom onset occurred on average at age 35.4 years. The most common complaints were pain and stiffness in the neck, shoulders, and lower back and headaches. Videotapes of 6 surgeons revealed problems with operating room setup, awkward posture, forceful exertion, poor positioning, lighting, and duration of procedures. CONCLUSION Symptoms of musculoskeletal injuries are common and may begin early in a physician's career. Modifying footwear, flooring, table height, operating position, lighting, and surgical instruments may improve the ergonomics of office-based surgery. [source] Circulatory arrest in late pregnancy: caesarean section a vital decision for both mother and childACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2009H. J. ZDOLSEK Circulatory arrest during pregnancy is extremely rare and there should be a well-planned strategy for its management in all hospitals. To consider the priority of the mother's life over the child's and an unwarranted pre-term delivery may lead to hesitancy and uncertainty and jeopardize both of them. In these situations, speed is a priority. Cardiopulmonary resuscitation should commence immediately. The anaesthesiologist should be well aware of the possible advantage of a caesarean section. Even if the obstetrician is responsible for the decision to perform the operation, the anaesthesiologist should strongly support the action. An ,emergency caesarean kit' with the essential surgical instruments should be immediately available in every labour ward and emergency department. [source] Motorization of a surgical microscope for intra-operative navigation and intuitive controlTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 3 2010M. Finke Abstract Background During surgical procedures, various medical systems, e.g. microscope or C-arm, are used. Their precise and repeatable manual positioning can be very cumbersome and interrupts the surgeon's work flow. Robotized systems can assist the surgeon but they require suitable kinematics and control. However, positioning must be fast, flexible and intuitive. Methods We describe a fully motorized surgical microscope. Hardware components as well as implemented applications are specified. The kinematic equations are described and a novel control concept is proposed. Results Our microscope combines fast manual handling with accurate, automatic positioning. Intuitive control is provided by a small remote control mounted to one of the surgical instruments. Positioning accuracy and repeatability are < 1 mm and vibrations caused by automatic movements fade away in about 1 s. Conclusion The robotic system assists the surgeon, so that he can position the microscope precisely and repeatedly without interrupting the clinical workflow. The combination of manual und automatic control guarantees fast and flexible positioning during surgical procedures. Copyright © 2010 John Wiley & Sons, Ltd. [source] Graphic and haptic modelling of the oesophagus for VR-based medical simulationTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 3 2009Changmok Choi Abstract Background Medical simulators with vision and haptic feedback have been applied to many medical procedures in recent years, due to their safe and repetitive nature for training. Among the many technical components of the simulators, realistic and interactive organ modelling stands out as a key issue for judging the fidelity of the simulation. This paper describes the modelling of an oesophagus for a real-time laparoscopic surgical simulator. Methods For realistic simulation, organ deformation and tissue cutting in the oesophagus are implemented with geometric organ models segmented from the Visible Human Dataset. The tissue mechanical parameters were obtained from in vivo animal experiments and integrated with graphic and haptic devices into the laparoscopic surgical simulation system inside an abdominal mannequin. Results This platform can be used to demonstrate deformation and incision of the oesophagus by surgical instruments, where the user can haptically interact with the virtual soft tissues and simultaneously see the corresponding organ deformation on the visual display. Conclusions Current laparoscopic surgical training has been transformed from the traditional apprenticeship model to simulation-based methods. The outcome of the model could replace conventional training systems and could be useful in effectively transferring surgical skills to novice surgeons. Copyright © 2009 John Wiley & Sons, Ltd. [source] Are the Brookhill,Wilk patents impediments to market growth in cybersurgery?THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 1 2008T. R. McLean Abstract Background In the past, many surgeons could practise their craft with little or no knowledge of patent law. But in the world of robotic and computerized surgery, this is increasingly a myopic approach, because the principle means of protecting high-tech surgical instruments is through the application of patent law. The issue is: does the Brookhill,Wilk patent, which covers the performance of remote robotic surgery, impede the growth of cybersurgery? Methods Review of the Brookhill,Wilk patent and relevant law. Results Patent law, which first took its form in the Middle Ages, attempts to balance the rewarding of innovation with the stifling of market growth. Using US patent law as a model, it would appear that the Brookhill,Wilk patent, a particular example of a medical process patent, could inhibit the growth of cybersurgery, as potential sums of money could be demanded by the patent holder from anyone who practises cybersurgery. However, two recent US Supreme Court cases appear to have seriously undermined the validity of a number of medical process patents, including the Brookhill,Wilk patent. Conclusion Based on recent changes in patent law, it is not expected that Brookhill,Wilk patent will hinder the growth of cybersurgery. Copyright © 2008 John Wiley & Sons, Ltd. [source] The legal and economic forces that will shape the international market for cybersurgeryTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 4 2006EKVAHSC, Thomas R. McLean MD Abstract Background Despite the common use of medical devices most health care providers have little understanding how a device alters medical malpractice litigation. Such knowledge will be increasingly valuable as cybersurgery (i.e. remote robotic surgery) becomes routine. Methods Review of the laws governing products and telecommunication liability. Results Litigation after cybersurgery will be complex. In addition to being able to sue physicians and hospitals, patients who sustain an adverse outcome after cybersurgery will have the potential to sue the robotic manufacturer and telecommunication company. Robotics manufacturers can obtain virtual immunity from liability if they elected to place their devices on the market after obtaining §360 per-market approval from the FDA. However, because §360 pre-market approval is expensive and time consuming most medical devices on the market (including the robotic surgical instruments) do not have immunity to products liability. Consequently, after an adverse cybersurgical outcome a manufacturer of a robotic surgical instrument faces liability for failure to warn, design defects, and failure to properly manufacture. As for telecommunication providers, existing law provides them with immunity from liability. Conclusions Litigation following cybersurgery will involve multiple defendants who are likely to use "finger pointing" defenses. Accordingly, there will be liability traps associated with providing cybersurgery. Copyright © 2006 John Wiley & Sons, Ltd. [source] Computer-aided navigation for arthroscopic hip surgery using encoder linkages for position tracking,THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 3 2006Emily Monahan Abstract Background While arthroscopic surgery has many advantages over traditional surgery, this minimally invasive technique is not often applied to the hip joint. Two main reasons for this are the complexity of navigating within the joint and the difficulty of correctly placing portal incisions without damaging critical neurovascular structures. This paper proposes a computer-aided navigation system to address the challenges of arthroscopic hip surgery. Methods Unlike conventional arthroscopic methods, our system uses a hyper-redundant encoder linkage to track surgical instruments, thus eliminating the occlusion and distortion problems associated with standard optical and electromagnetic tracking systems. The encoder linkage position information is used to generate a computer display of patient anatomy. Results The tracking error from the encoder linkage was evaluated to be within an acceptable range for this tracking prototype, and the new computer-aided approach to arthroscopic hip surgery was applied to a prototype system for concept verification. Conclusion This navigation system for arthroscopic hip surgery can be used as a tool to address the challenges of joint navigation and portal placement in arthroscopic hip surgery by visually supplementing the limiting view from the arthroscope. The introduction of a tracking linkage shows significant potential as an alternative to other tracking systems. Positive feedback about the completed demo system was obtained from surgeons who perform arthroscopic proceduces. Copyright © 2006 John Wiley & Sons, Ltd. [source] Temporary Intermaxillary Fixation using Individualized Acrylic Splints Permits Image,Data-Based Surgery of the Lower Jaw and OropharynxTHE LARYNGOSCOPE, Issue 8 2004Jürgen Hoffmann MD Abstract Objectives/Hypothesis: Image,data-based surgical navigation is used as a helpful device in the operating room to localize critical structures with a high degree of accuracy. It also enables physicians to plan therapeutic performance. Because it relies on preoperatively acquired computed tomography (CT) or magnetic resonance imaging (MRI) data, there is restricted access for navigation of surgical instruments in areas that show motion uncorrelated with radiologic data. Thus, in the case of moveable structures, for example the lower jaw, navigational procedures could not yet be applied. Study Design: We introduce a new technique using individualized intermaxillary splints that fix the mandible in a reproducible aboccluded position at the time of image-data acquisition and surgery. Methods: Different manufacturing processes were investigated. The feasibility of uni- and bilateral intermaxillary splints was studied under clinical conditions in four patients during different procedures in the mandibular and oropharyngeal regions. Results: The manufacturing of the splints showed was easily performed in a short time. With bilateral fixation, there was a high anatomic target precision of 1.6 to 2.3 mm. Conclusions: The use of bilateral intermaxillary splints that fix the patient's mandible in a reproducible aboccluded position permits an image,data-based navigated surgical approach to the oropharyngeal and mandibular regions. [source] Experimental model for analyzing cutting resistance by various knives for cataract surgeryCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 3 2010Takeshi Ide MD PhD Abstract Background:, The trend in current cataract surgery towards clear corneal incision and sutureless procedures makes us realize the importance of wound construction. For optimal surgical outcomes, we need good surgical instruments. In this study, we employed a resistance recording system to analyze the characteristics of seven commercially available disposable cataract knives and to find clues for the future development of ,good' cataract knives. Methods:, The cutting resistance was recorded during perpendicular penetrations of porcine scleral tissues by cataract knives. This data was processed and analysed mathematically with MATLAB software (The MathWorks, Inc, Natick, MA, USA) to see the resistance wave shapes and their derivatives to show the products' differing characteristics. Results:, The wave shapes demonstrated product-dependent characteristics. The average maximum penetration resistance varied from 86.4 to 233 mN. The first order time derivatives also showed distinctive wave shapes. Conclusion:, We used an experimental model to analyze one aspect of a knife's character. This model can help give clues for future developments, although this is the initial step. [source] | ||||||||||