Research On Real-time Robotic Navigation System For CT-guided Minimally Invasive Treatment

With the development of CT-guided minimally invasive technique, it has played an important role in the treatment of tumor, spine diseases and osteoarthritis. There are many obvious advantages such as lower cost, less trauma, rapid recovery and better curative effect. As far as the application of CT-guided minimally invasive technique be concerned, what the most critical procedure is how to puncture accurately and place needles conformally. Biopsy without guidance is widely accepted by many doctors, which depends heavily on the skills and experience of doctor. Moreover, the 3D conformal needle placement requires a higher ability to spatial imagination, which would contribute to the limitations of the technique, such as relatively low accuracy and effectiveness, incomplete tumor and high rate of complication. Currently, there are varied kinds of CT navigation systems to improve the accuracy, some of which are really helpful, but there are still some flaws in these CT navigation systems. Respecting its characteristics, this research is based on the clinical needs, and to combine navigation technology and robotic technology into the clinical treatment in order to design and develop a new set of robotic navigation system for CT-guided minimally invasive treatment.There are several problems in combining the real-time navigation system into the CT-guided minimally invasive treatment, which involves medical and engineering problems, navigation, robotic technique, imaging technology, rebuilding and clinical treatment techniques. The real-time navigation systems should meet three basic requirements:easy operation, accurate guidance and safety. The core technology includes four aspects:(1) How to design the framework for CT-guided navigation robot system. This system is referred to choosing, infusion and optimization among several different techniques. Meanwhile, according to the clinical requirements choosing the optimized techniques is the most critical. By optimization and combination, the efficiency of robot navigation system has been greatly improved. (2) Development of robot navigation system hardware. The hardware mainly includes two parts, which are location platform and puncture mechanical arm. It’s also important to consider the placement of two parts, which must fit the surgery room well. (3) Design the software of the navigation system. It comprises two parts:navigation system and control system. The navigation system can provide images on different levels so that it can give the doctors information on how to conduct the operation. The controlling system can accurately control the robotic arms to do all required actions safely. (4) Detecting and compensation of physiological movements. It mainly aimed at inspect and adjust patient’s respiratory movement and other physical displacement.The main contents of this dissertation are as follows:1. Compare all three positioning techniques:magnetic, optical and mechanical system. Based on the test results, the magnetic positioning technique has been taken to design the framework of CT-guided navigation robotic system.2. Exploration of both hardware and software of the puncture robotic arms, including electrode controlling module, communication module and signal processing module. According to the clinical needs, we have designed and successfully manufactured a five-degree freedom puncture mechanical arm. Its accuracy and handiness have been justified by partial experiment, phantom experiment and animal experiment.3. Design and develop operational software for the navigation robotic system. By analyzing the phantom experiment and animal experiment, we figured out that a friendly operational interface which should be capable of providing images at any level, which can shows the position of mechanical arm ending, the exact positions of needles and target points, and mark the treatment area as well.4. Research and apply techniques to inspect and balance patient’s respiratory movement and other physical displacement. By inspecting the datum points on the body surface and the position of the puncture needle, this navigation system can provide real-time guidance. Through phantom experiment and patients’ breathing test record markers to find the precise motion law of periodicity. According to the respiratory gating module and the respiration curve, puncture on expiratory phase can be conducted.To meet clinical requirements, this research has developed a new set of CT-guided minimally invasive treatment cooperated with real-time navigation robotic system, which is based on the magnetic positioning technology. The combination navigation technology into robotic technology can improve the procedure in accuracy and safety of the minimally invasive treatment. However, this system should be further improved in the future. In afterwards research, we are aimed to improve the interaction between doctor and machine in order to provide effective services for patients.