Research On Vascular Interventional Surgery Robot For Transcatheter Arterial Chemoembolization

The application of minimally invasive technology makes the operation farewell to the traditional open wound operation mode and ensures the rapid recovery of the patients after operation.Transcatheter arterial chemoembolization(TACE)is a typical representative of minimally invasive treatment,but the current interventional operation mode requires physicians to operate the guidewire/catheter in the on-the-spot radiography environment.Even wearing heavy radiation protective clothing,working in harmful radiation for years still causes irreversible injury to interventional physicians.In this paper,an interventional robot system for liver embolization is studied as the breakthrough point of the research.Based on the actual TACE surgical procedures and the analysis of existing relevant interventional machine system clinical reference deficiencies,a 4-degree-of-freedom and multi-function interventional surgical robot system is proposed to cover the practical clinical needs as comprehensive as possible while minimizing human indoor operations.First,the mechanical design of the TACE robot is illustrated.A removable mount module docking method is designed to realize the modular design of the slave actuator of the robot and the electronic passivity of the 4-degree-of-freedom of guidewire/catheter delivery and twisting motions cooperatively or independently.By increasing the number of controllable micro motor control and reasonable transmission system design,the related multi-function structure is made as simple as possible.And four collaborative functions of guidewire controllable clamping,swing wheel locking,guide wire retreat motion by friction wheel rolling and Y-connector’s end locking are realized.Meanwhile,a novel and micro guidewire delivery resistance sensing mechanism based on the sliding form of spring clamp-ball slider is proposed,by means of effective control of friction and weight of the fixture,the resistance sensing mechanism can accurately evaluate the delivery resistance of guidewire at different angles without relevant force compensation algorithm.Second,the related control system and data interaction method of the robot system are introduced.Based on four encoders,the motion following system of guidewire/catheter delivery and twisting is designed while the corresponding multi-function controlled through micro stepper motor station is built based on CAN.And the resistance of guidewire delivery motion is built through a hysteresis brake installed on the test master controller.Based on the description of the mechanical structure and system control section,a double input single output fuzzy controller model is used to realize the fusion of delivery force and delivery resistance fluctuation.Combined with a custom supplementary rule design,the test experience is transformed into a digital hysteresis brake torque braking strategy to improve the intelligence of the machine system.In addition,based on the fuzzy control theory,a bending feedback method is discussed for the bending tube placement problem derived from robot instead of conventional interventional surgery.Combined with the deep learning YoloV4 model,the network parameter weight file is trained and a dynamic detection framework is built in Lab VIEW environment.The catheter delivery situation is evaluated in a simplified environment through TCP data interaction and simple fuzzy rule mapping design,the value of motion following scaling factor is designed to be determined by robot independently.At the last part,the overall design of the TACE robot system is introduced,the device loading and the related motion control tests of the 4-degree-of-freedom and multi-function design are carried out.The modular design of the robot system makes the device mounting process simple enough and the related motion control is as expected.