# A Novel Vascular Intervention Surgical Robot Based on Force Feedback and Flexible Clamping
## 1 Introduction  
Vascular interventional surgery means that under the guidance of medical imaging, the doctor manipulates the catheter or guidewire into the human blood vessel through a small wound and then moves to the lesion for treatment, so as to embolize the malformed blood vessel, dissolve the thrombus, dilate the narrow blood vessel and so on [1; 2; 3]. However, doctors who have been exposed to radiation for a long time cannot completely eliminate radiation hazards, even if they wear radiation-proof lead clothing [4; 5], and heavy protective clothing will also bring doctors cervical or lumbar pain [6]. In addition, due to the bending and narrowing of human blood vessels and their many branches, the doctor is required to not shake too much during the operation. As such, the doctor should be highly focused during the operation, which can easily cause fatigue in the doctor, thus leaving him or her unable to guarantee the success and accuracy of the operation [7]. The application of robot technology to the field of vascular interventional technology can largely relieve the burden of doctors and free them from the high radiation environment [8]. With the help of robot technology, surgical safety and accuracy can be improved, and the accidents caused by human fatigue factors can be reduced [9; 10]. In recent years, several commercial vascular intervention surgical robot (VISR) systems have been developed. For example, the Sensei robot system developed by Hansen Medical has been successfully used in clinical applications in different fields for remoteoperations using operable catheters and jackets [11; 12]. The Amigo robot system, designed by Catheter Robotics, has three degrees of freedom and can carry out such actions as the propulsion of the active catheter, twisting the catheter and bending the catheter head [13; 14]. The Niobe robot system developed by Stereotaxis Incorporation manages the position and incorporation of the catheter by using magnetic navigation technology [15; 16]. All three are active catheter systems, but issues such as the size and safety of active catheters limit their use in cardiovascular surgery, compared with the wide range of passive catheters. Currently, the most mature passive catheter system is the Corpath GRX robot system [17; 18; 19] developed by Corindus Vascular Robotics, which includes a wire feeder and a remote operating station for the operation of catheters, guidewires, balloons and other instruments. In addition, some research institutions have also conducted research in this field, such as Hanyang University, the University of Western Ontario, the Beijing Institute of Technology and Shanghai University [20; 21; 22; 23]. In remote interventional surgery, in addition to the guidance of medical images, doctors also need to use the assistance of robots to judge whether the front end of the guidewire touches the blood vessel [24]. Therefore, the establishment of force feedback has become an important factor affecting the success rate of a surgery, which includes two aspects: the accurate detection of proximal force at the slave end and the formation of force sensation at the master end. However, most of the VISR system only tests the proximal force without providing the operator with a force sensation [25; 26]. Otherwise, some agencies use commercial master manipulators, such as the Geomagic Touch X system developed by 3D Systems, which is not flexible enough for vascular intervention surgery and is not in accordance with traditional surgical operations [27]. During an operation, doctors use their fingers to propel and twist the catheter or guidewire, which can sense the degree of clamping and adjust the clamping force in real time. When the VISR is used for surgery, there are two methods for clamping the catheter or guidewire: rolling transmission with a friction wheel [28] and reciprocating propulsion with a sliding platform [29].