Robot Assisted Total Knee Replacement Surgical System And Its Preclinical Applications

With the development of computer science, computers have been widely used in all fields of human life. Without exception, the computer technology is revolutionizing the medical field with the creation of robotic devices and complex imaging. Especially in Orthopedics, there is a well-recognised relationship between accuracy and outcome: accurate operation technology can improve the operation performance. Because the traditional (hand-controlled) orthopaedic tecnhology heavily relies on a surgeon's experience, it certainly increases the instability of the surgery. However, computer assisted orthopaedic surgery (CAOS) system can provide high accuracy and stability for orthopaedic surgery for its unique features, so CAOS is becoming a hot research topic. Computer assisted orthopaedic surgery (CAOS), also known as image-guided orthopaedic surgery, surgical navigation, and robot assisted orthopaedic surgery, is any computer-based procedure that utilizes robotic or navigation technologies in the planning, execution and follow-up of orthopaedic surgical procedures.Up to now, many application systems, which equip their surgical robots with different surgical navigation system, have been proposed. However, they all have their own shortcomings. To further improve the accuracy of implant alignment and overcome the shortcomings of current CAOS systems, we developed a new CAOS system WATO, which integrates the imageless navigation system (stereoscopic equipment) and the active robotic system into a hand-eye robot.The thesis consists of six sections. In the first section, the research on CAOS in the world has been studied, and its advantages and disadvantages are discussed. In the second section, we give an overview of manual TKR surgery and robot assisted TKR surgery. In the third section, the system structure, the positioning theory and the operation rules of WATO are introduced. We focus on the camera calibration and the hand-eye calibration technologies for WATO in the forth and fifth section. In the sixth section, the test experiments of WATO are introduced. The experimental results are also analyzed.The thesis'main research work and major contributions are as follows:(1) Based on the current CAOS systems, we developed a new CAOS system, which integrates the imageless navigation system (stereoscopic equipment) and the active robotic system into a hand-eye robot. According to the properties of TKR surgery, the tibia and femur measurement methods and the surgery position algorithm in WATO are illustrated.(2) According to the proposed technologies in the references, three new camera calibration methods are proposed in the paper. The first one of them is the camera calibration algorithm based on projected circle centers; the second one of them is the multi-camera calibration algorithm using 1D objects; the third one of them is the camera calibration algorithm using 1.5D objects. They are all accurate, robust and suitable for WATO.(3) The traditional hand-eye calibration conception and method are simply summarized. A new hand-eye calibration algorithm based on screw motions is proposed in the paper. It is simple and accurate, and ensures the safety of WATO.(4) A new practical visual servo algorithm is proposed in the paper. It is a guarantee of adjusting the position of surgical robot due to the tiny motion of the bones.