Project Success Stories - A cut above: robots in the operating room
When you hear the word 'surgery', the image of an incision large enough for the surgeon to see and feel the organ with his own eyes and fingers comes to mind. Sometimes the damage done to the skin and muscle, to access the region of interest, causes greater injury than the curative procedure itself. This long incision is the scarlet letter of traditional surgery. Not surprisingly, the trend is now moving towards minimally invasive surgery, performed through small incisions in the patient's skin to preserve healthy organs and tissue. Typically, surgeons insert two small tubes and use what are called endoscopes. One carries a fibre-optic camera and light source; the other carries miniaturised surgical instruments. The surgeon works with long, slender instruments that provide very little feedback and offer a limited view of the operating area through a single camera. This method also requires good hand-eye coordination. That is why many complex surgical procedures still have to be done in the traditional 'more invasive' way. Next up: robotic surgery The Karlsruhe Institute of Technology (KIT) in Germany and its partners' goal with the Accurobas project was to overcome these limitations through robotics. While it may sound futuristic, robotic surgery is an extension of minimally invasive techniques. The difference is that the surgeon uses robotic arms instead of endoscopes and tools, like the scalpel and clamp. The robots under investigation in the Accurobas project belong to the new class of lightweight robots which leave a very small footprint, suggests the project manager, Dr Joerg Raczkowsky at KIT. 'They could be easily configured for the specific demands of the actual operation,' he says. Mirosurge is one such surgical robot which can assist the surgeon directly at the operating table. Designed at the German Aerospace Centre (Deutsches Zentrum für Luft- und Raumfahrt - DLR), the robot consists of three MIRO® robotic arms which are inserted in the patient's body through small incisions. One arm guides a laparoscope - a telescope-like endoscope - and two act as the surgeon's hands. Across the operating room, the surgeon sits comfortably in front of an ergonomically correct stereoscopic viewer. The displays show real-time, high-resolution video feed collected by a pair of cameras on the laparoscope. The surgeon can look through the viewer straight into the patient and the operating area. As he moves his hands, the robotic arms inside the patient's body mimic the surgeon's movements - cutting and suturing. Soft actuators allow him to move the robot arms around with ease. More importantly, miniaturised torque-capture sensors provide feedback on the reaction forces, putting the surgeon back in contact with the tissue being manipulated. Beyond the limits of human dexterity This new surgical robot allows surgeons to perform operations with unmatched precision in a way that reduces the risk of complications and actually requires less staff during the surgical procedure. The patients benefit from the smaller incisions, less post-operative pain, and a faster recovery. 'It's a far cry from the massive scars and long hospital stays of traditional "open" surgery,' says Dr Raczkowsky. And due to the better ergonomic conditions, the surgeon becomes less fatigued and can produce better results for patients. Specifically, with dimensions similar to those of the human arm and their low weight of 10 kilograms, the MIRO® robotic system gives surgeons seven degrees of freedom of movement - just like the human wrist. Furthermore, because a computer digitises the movements, any hand tremors or jerks are transformed into the smooth, continuous movements necessary for a delicate procedure. The high-performance laparoscope has two independent vision channels. Merging the two images provides the surgeon with accurate depth perception. The robotic system also incorporates image processing software for edge-enhancement and noise-reduction. The resulting high-resolution three-dimensional (3D) image is bright, crisp and clear. But perhaps the most promising function in terms of human-robot interaction is eye-tracking - calculating the 'fixation point' of the surgeon's gaze onto the 3D display which represents the operating area. This information can then be used in numerous ways; for example, it can be used to stop a beating heart! Widely termed gaze-contingent motion stabilisation, it uses information relating to the depth of the tissue and the frequency of change of depth, and adjusts the camera and instruments automatically to move with the same frequency and on the same plane. In effect, allowing the surgeon to operate on what is essentially a still image. Looking to the future Clearly, the future of surgery is in robots, as European researchers with the Accurobas project seem to believe. Using something like Mirosurge can improve the consistency and accuracy of surgery. This precision surgical assistant is establishing a new paradigm for how surgery is done. 'The surgeon will function as integrated supervisor,' says Dr Raczkowsky. While the applications are vast, the new Accurobas technologies require mastery by the surgeon. Given also the complexity of surgical procedures and the high incidence of unexpected complications, the day when sophisticated robots reigns in the operating room may still be some time away. Serious questions remain to be answered, especially for robotic devices that actually operate on humans. Because they may pose a significant risk to the patient's health, robotic arms are being evaluated not only for effectiveness but also for safety. The first tests in the laboratory revealed a clear benefit in using lightweight robots for two different procedures: laser osteotomy and palpation. During osteotomy, a bone was either shortened, lengthened or its alignment changed using a carbon dioxide laser. Palpation, on the other hand, involved the physical examination of a patient where tissue or an organ is felt to determine its size, shape and firmness and position. After the end of the project in 2009, three partners - the University of Verona in Italy, KIT in Germany and the German Aerospace Centre - clinched almost EUR 3.9 million under the Seventh Framework Programme for the continuation of Accurobas as the 'Patient safety in robotic surgery' (Safros) project. Meanwhile, the Altair Lab at the University of Verona started a spin-off company not only to industrialise, but also to commercialise the promising technologies developed during the Accurobas project. Altairmed srl is committed to accelerating the adaptation of precision robotic assistants in minimally invasive surgery. The Accurobas 'Specific targeted research project' (STREP) received more than EUR 3 million of EU funding under the 'Information society technologies' (IST) theme of the Sixth Framework Programme for research.