Research On Key Technologies Of Cerebrovascular Interventional Surgery

Since the beginning of the new century,people’s living standard has been improving rapidly.At the same time,the phenomenon of hypertension and hyperlipidemia is becoming more and more common among people,and the number of patients with cardiovascular and cerebrovascular diseases is also increasing,which seriously threatens people’s health.According to relevant statistics,the death rate of cardiovascular diseases among middle-aged and elderly people is ranked first among all diseases,and the trend is still increasing.In current medical technology,the most effective treatment option for cardiovascular and cerebrovascular diseases is vascular interventional surgery.However,there are still many problems that need to be solved during the vascular interventional procedures.First of all,the process of wire delivery for interventional procedures is time-consuming.An interventional procedure often takes several hours to complete and requires a high level of concentration throughout the procedure,which can be physically demanding.In addition,doctors are less efficient in manually operating the guidewire for pushing,and it often takes several attempts to deliver the guide wire to the target lesion.Finally,in order to obtain information about the patient’s vascular contours,X-rays need to be irradiated several times in the operating room.In order to avoid radiation damage caused by X-rays,doctors need to wear heavy lead suits during the whole procedure,which further increases the burden of the doctors.The emergence of the cardiovascular and cerebrovascular interventional robot system has undoubtedly solved this problem.By operating the interventional robot,the surgeon can no longer enter the operating room and avoid radiation damage from X-rays.In addition,the high-precision operation of the interventional robot can effectively improve the efficiency of the operation and reduce the operating burden of the surgeon.This paper focuses on the issue of interactive control of vascular interventional surgical robotic systems.Firstly,this paper introduces the traditional cardiovascular and cerebrovascular interventional procedure,and extracts two key operations in the whole complex procedure:pushing and twisting of the guidewire.Subsequently,the DSA imaging sequence of the patient is analyzed.The angiographic images under each frame are enhanced by combining a Hessian matrix with a Gaussian filter with variable scale parameters;the vessel images are further segmented by a Frangi filter;and the overall contour map of the vessels under the current moment is obtained by image fusion.It is prepared for the subsequent Dijkstra algorithm to find the ideal filament feeding path,the autonomous operation mode of vascular intervention and the master-slave control mode.Secondly,a greedy criterion-based slave-side autonomous filament delivery algorithm is proposed for simple scenarios such as no blockage and complex branching of the vessel in the filament delivery process.The Dijkstra algorithm is used to extract an ideal wire feeding path in the vessel contour image,and the general problem of how to push the guidewire to the location of the lesion is transformed into a series of subproblems of how to rotate the guidewire to the closest ideal wire feeding path at the current moment.The Lagrangian multiplier method is used to solve the current subproblem as a local optimum,and all the obtained local optimum solutions are summed to obtain the overall optimum solution of the original problem.Finally,simulation experiments are performed in MATLAB to compare the actual wire feeding path with the ideal one to verify the effectiveness of the method.Thirdly,a master-slave wire feeding algorithm based on teleoperated bilateral control is proposed for complex surgical scenarios such as excessive vascular bifurcation and vascular blockage,when it is difficult for the slave-side autonomous wire feeding algorithm to complete the autonomous wire feeding task.By analyzing the traditional tele-operated bilateral PD control algorithm,a new control scheme is designed for the problem of conflicting controller parameters in the slave’s free motion and non-free motion states,so that it can switch the corresponding control mode autonomously according to the changes of the slave’s environment.After the stability and transparency analysis of the method,simulation experiments were conducted in the Simulink environment of MATLAB.Finally,the experimental platform of the vascular interventional wire feeding robot device was built.The effectiveness of the proposed method was verified by operating the hand controller to achieve precise control of the slave end and pushing the guidewire to the predetermined target position.